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How to select the correct filter size for your swimming pool

How to Select the Correct Filter Size for Your Swimming Pool

A pool is a big responsibility and it needs a lot of maintenance, there are a great many things you will need one you have had your pool installed. Most important of that is the pool filter. How to know what size of filter would be perfect for your pool. Here is how you can select the best pool filter.

  • To select the appropriate size for the filter you will need the surface area as well as the water volume of your pool. The most common type of pool shape is either rectangular or round. The formula for calculating the surface area is L x W for a rectangular pool. If you have a round shaped pool then you take the radius to raise it to the power of 2 and then multiply that with 3.14. Most of the newly installed pool comes with all the measurements, so there will be no need for calculations.
  • To determine the size of your filter you will need to calculate the volume of water to get the right measure of the flow rate. The flow rate is the rate of water that goes through the filter in a minute. The volume of water is given when you purchase the pool, dived that number with 360 this will give you the rate of a gallon that will go through the filter in a minute. The flow rate will help you find the best possible filter for your pool. Every filter comes with lowest and highest flow rate. The pump needs to accommodate that flow if the flow is too high or too low the filter will not work properly.
  • Find the pool’s turnover rate. Runover rate is the measurement of how much time does it take for the water to fully rotate through the filter. Once every 12 hours is the standard for any backyard pool.

Our swimming pools need to be kept always clean. But then, how can this be achieved? This is by the use of pool filters. They are the most important parts of our pools; they are what keep our swimming pools clean. Without them, never expect to have a clear pool at any time. A pool that isn’t clean is identified by being cloudy and green. The filters are responsible for taking off fine particles from the water as the water is kept flowing consistently preventing it from being stagnant.

For all this to go the right way possible, choosing the correct filter is important. Without knowing what you need while out in the market, you will actually get yourself falling at bringing home something that is not ideal for you. Before deciding to go shopping, you need to first know every detail of your swimming pool, this is what will be guiding you while checking on the one you need. Here are steps to follow in this.

Find the volume of water your pool holds and it’s the surface area

You will find different pools with different shapes, but then, the common pools are round and rectangular in shape. Depending on the shape you own, it is important you correctly calculate the size of the pool using the right mathematical formulas. It will also be well to measure the surface area of your pool yourself, but then if in case you had purchased it, the measurements obvious should have been provided to you by the seller upon purchase.

Find out the maximum volume of water of your pool

After you have done this, you will make use of the volume of the pool to identify the amount of water that moves through the pool filter in every minute. This is actually what is referred to as the flow rate. The rate normally differs from one pool to the other. This need to be calculated having in mind that you are after purchasing the filter that will work best with your pool to maintain it clean. Also what you should consider is purchasing a pool filter that is slightly oversized for the pool you own; this will ensure there is maximum efficiency.

In case you find that the flow rate exceeds and that this operation turns to pressurize the filter too much, all you need to consider is increasing the size of the pipe of your plumbing system in whole or part of it. This will in turn help to reduce the system operating pressure.

Actually, all filters you will find out there have a maximum and minimum rate of flow that the pump that needs to be falling within. The filter will not at all function properly if it’s too weak or there happens to be too much flow. Ensure you choose a pool that accommodates well the amount of water your pool holds.

Find out the turnover rate of the pool

What does this mean? You need actually to know the time it takes for the water in the pool to cycle completely through the pool filter. Out there, most municipal health codes normally need a minimum turnover filtration rate of two complete water turnovers in a period of 24 hours. The turnover rate termed as the minimum is the one that makes to turn over the whole swimming pool in a period of 12 hours one complete cycle. The typical sizing rates for swimming pools these days are about 8 to 10 hours.

For swimming pools for semi-commercial, commercial or experiencing high turnover application, then it is important to buy a filter that is capable to turn over all water in the pool at least every 24 hours complete four cycles.

Choose the right filter

A factor that is more dependable when choosing the right pool filter is the size of your pool. There is a need to run the pump each and every day to ensure water clarity of your pool is maintained. This ensures that the water is completely turned over. The turnover rate and designing rate of all filters is at a gallon per 60 seconds.

Consider the amount of water resistance that brings an effect on the Polaris turnover rate

There will actually be more resistance when water will tend to move faster through the pump. Opt for a pool filter that will turn your pool in a period of 10 hours as the minimum turnover rate. Going for bigger filters is good for filters as large filter areas actually help to maintain the clarity of your pool water.

Also, you need to remember that the faster the water velocity that moves through the system, the great forces of resistance of water flow will be experienced. What does this mean? A slower pump like for instance the one with a speed of the 2-speed pump will be having a flow increase on lower speeds per unit of power as compared to those with high speeds.

Use all the gathered information from the swimming pool to make the right filter purchase of your pool. You will not at all experience any problems when you use a simple equation when doing this. Before you place everything together, ensure that you have calculated the volume of the pool correctly in gallons and try to make a decision on a turnover rate that is reasonable for all water that the filter will be cycling.

It can be something important to the lives of our loved ones and us too by maintaining the cleanliness of our pools. This is why you need to go for the right pool filter to help you perform all these so that you will always remain to enjoy your swimming pool always. Out of the filter options, you will find in the market, you need to consider the one that is the best fit for your pool and also the one that favors your budget. A pool filter is among the great investments and actually the most useful and easiest way of keeping our swimming pools clean.

Choosing the right size pool filter for your pool is not always a simple task, but it is crucial to ensuring that your pool stays safe, clean, and open. The first step when picking the right sized pool filter is picking the right size pool pump.

Choose the Right Size Pump

Many people err on the side of caution and purchase a pump that is far bigger than what they need. This can be a costly mistake. Larger pumps are more expensive, and may increase your energy bill compared to an appropriately sized pump. Worse, a pump that is too large can overpower your filter system. A pump that is too small may lack the power needed to effectively pump and filter your pool. This can lead to a buildup of bacteria and algae.

Choose the Right Size of filter

Even if you have the right sized pump, if you choose a filter that is too small, the pump will generate too much pressure, causing the filtering material to break down and rendering the filter ineffective. The pressure build-up caused by small filters causes pressure to build up in your pump, and in some cases this has resulted in explosions, or serious damage to your pump.

The correct sized filter and pump should be able to fully cycle all of your pool water in about eight hours. This simple guide will show you how to find the right sized pump and filter for your pool.

How to Select the Correct Filter Size for Your Swimming Pool

Step 1: How Much Water Does Your Pool Hold?

The first step to picking the right size pool filter is determining how much water your pool actually holds. This is a relatively easy process if you have a nice simple rectangular pool, but gets progressively difficult the more intricate your pool layout is. Broadly speaking however, there are four pool shapes: rectangular, round, oval, and kidney. To determine the size of your pool there are some simple formulas to use.

Pool depth: Regardless of the shape of your pool you’ll need to calculate the average pool depth. To do this simply find the deepest part of the pool, and the shallowest part and find the average between them. If the deep end is 12 feet and the shallow end is 4 feet, then the average depth would be 12+4 = 16 and 16 ÷ 2= 8.

Rectangular pools: You’ll first have to measure the length and width of your pool. Remember that old formula from elementary school: A=L x W (Surface Area= length x width)? Use it to find the surface area.

Next, find the average depth of your pool. Multiply the average depth by the surface area to find the total volume. Or, wrap it all into one formula: L x W x D = V. This is the volume of your pool. If your pool is “L” shaped then break it into two (or more) rectangles and calculate the volume of each, then add the volume together.

Round pools: Determining the surface are of your round pool requires a slightly more complex formula. Surface area (SA) = pi (which is 3.14) x the radius squared (r2). So your formula looks like this: SA = 3.14 x r2. Then calculate the average depth of your pool, and multiply it by the volume.

Oval pools: Oval pools are a bit trickier, you’ll have to measure the longest diameter, shortest diameter, and average depth and use this formula: longest diameter x shortest diameter x average depth = volume.

Kidney shaped pools: You’ll have to find the longest width, shortest width, and length of your pool. Then calculate the volume with the following formula: Volume = (longest width + shortest width) x length x average depth.

Step 2: Turn Cubic Feet into Gallons

Once you have calculated the volume of your pool in cubic feet, multiply that figure by 7.48 – which is how many gallons there are in one cubic foot.

How to Select the Correct Filter Size for Your Swimming Pool

Step 3: Gallons Per Minute

Once you have calculated your total pool capacity in gallons you need to calculate the gallons per minute that you will want your pump to handle. Remember that most pool owners look to run their pump for no more than 8 hours. So that means you need to determine how many gallons per minute you need. First divide your pool’s volume (in gallons) by 8, this will give you gallons per hour. Then divide that number by 60, because there are 60 minutes in an hour. The average pool is about 20,000 gallons which means that 20,000 ÷ 8 = 2,500 GPH (gallons per hour), and 42 GPM (gallons per minute).

For commercial pools, or other heavily used applications you ideally want to be able to run your pool 4 times within 24 hours, meaning you want a total pump in 6 hours or less.

Step 4: Feet of Head

You need to take into consideration the piping between the pool and the pump (called the feet of head). The more head you have, the more that GPM will decrease. You’ll also have to take into consideration any fixtures and valves in the piping as well. You should at least have a rough estimate of how many feet of piping are between your pool and pump.

Step 5: Choose Your Pump

Once you know your GPM and feet of head you can start searching for the right pump. Most pump manufacturers and retailers will provide a chart indicating the pumps GPM capacity based on different foot of head lengths. It is always better, once you know your pool’s capacity and pump requirements to buy a slightly larger pump.

Step 6: Choose Your Filter Size

Your pool filter size is directly related to the size of your pump. Too small and the filter could break, and your pump could burn out. There are less risks associated with buying a filter that is too large than one that is too small, so keep that in mind while finding your filter. Then match your filter to at least the pumping capacity of your pump, so if your pump is good for 42 GPM, get a filter that is rated for 42GPM or more.

Additional Factors to Consider

You should also take into consideration a number of other factors. If you have waterfalls, spas, or other water features then they will add to your pools total GPM needs. If you have a very large pool (with a GPM that is more than 60) then you may not only need a larger pump, but also 2” diameter pipes which can handle up to 100 GPM.

How to Select the Correct Filter Size for Your Swimming Pool

Next Steps

Now that you know how to determine the right filter to purchase for your pool, you can shop for products that will suit your specific needs!

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Pool filters are as important to your pool as your kidneys are to your own body. We know that sounds kind of gross, but it’s true. Though chlorine and other sanitizers work to kill bacteria and other contaminants, the filter is what actually removes them from the water. Without it, your pool water would grow cloudy and fill with debris. Not exactly fun for swimming.

So how do you choose the best one? It’s not about which one is the least expensive, though cost is certainly a factor. You want a filter that will trap contaminants, be easy to clean and maintain, and last more than just a few seasons. In order to make the best selection for your pool, first get a handle on your options.

Pool Filter Types

The first step to choosing the best filter is knowing what your options are. You have three types of filters to choose from: sand, cartridge, and diatomaceous earth, or D.E. Price, replacement frequency, and filtration rates differ by type. And if you’re wondering how to clean a pool filter, that will also depend on the type you select.

But before you can accurately compare pool filter types, how well they function, and how much work they require to maintain, you need to know about microns.

What the Heck is a Micron?

Pool filters measure the size of contaminants they’re capable of removing in microns. It’s short for micrometer, which is one millionth of a meter.

Having trouble picturing just how small that is? A single strand of human hair is about 50 microns, or about .05 millimeters in diameter. Some bacteria measures about 2 microns, or about .002 millimeters in diameter.

How to Select the Correct Filter Size for Your Swimming Pool

Whether they’ve been killed by chlorine or not, bacteria and other contaminants can only be filtered out if the filter media—the material that actually does the filtering—is fine enough to collect those teeny, tiny particles.

Sand Filters

If you’re on a budget, and you want to spend minimal time on maintenance, a sand filter is the best choice for you. It’s also optimal for large pools because it won’t clog as easily as other filters.

Your pool pump sucks water in from the skimmers, then pushes it through a large filtration tank full of sand. The standard media used inside the tank is #20 silica sand. It grabs particles that measure 20 microns and larger.

Each grain of sand is, for lack of a better word, prickly. If you could look at it under a microscope, you’d see it has lots of little rough edges all around it, which is how it grabs contaminants and debris that pass through the filter.

As weeks and years pass, and more water flows through the filter, those rough edges are slowly worn down by erosion, eventually becoming smooth surfaces that aren’t able to capture anything.

At the same time, the particles trapped within the sand will build up over the life of the filter. This can actually help trap smaller particles, even as the sand itself begins to smooth out. But eventually, it will prevent proper water flow through the filter, reducing the filter’s efficiency.

A pressure gauge on the side of the filter will alert you to increasing internal pressure—a sign it’s time to backwash the filter. This easy cleaning method the filter reverses the water flow, flushing all the debris to waste.

Because the silica captures particles of 20 microns or larger, you’ll really need to stay on top of your pool water chemistry. If there’s not enough sanitizer in your pool to kill those tiny, 2-micron bacteria, a sand filter isn’t going to catch them either, and they’ll be floating around in your pool with you.

Sand, Cartridge, and Diatomaceous Earth (DE) Filter Systems

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How to Select the Correct Filter Size for Your Swimming Pool

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There is a lot of confusion about various filters, many different opinions, and several important facts to consider. The first is that a pool can be properly maintained with any of the filter systems available: Sand, Cartridge, or Diatomaceous Earth (DE). Here is a brief description of each type:

Sand Filters

Water is pushed through a bed of filter sand and removed through a set of lateral tubes at the bottom. The filter area of a sand filter is equal to the area of the filter itself.

For example, a 24″ filter will have 3.14 square feet of filter area. Only the top 1″ of sand is actually used to filter the water. The principle behind this filter is that water is pushed through the filter sand, somewhat like an espresso machine. Dirty water goes in the top and clean water exits out the bottom. As the filter sand becomes plugged with debris from the pool, the pressure increases on the filter and the water flow drops. In order to clean the filter, you just run it in reverse and dump the waste water; this is referred to as “backwashing” the filter.

Once the filter is backwashed, you move to the rinse mode and that repacks the sand and then back to filter. This has to be done manually every few weeks. From a hydraulics standpoint, a backwash valve is typically the most inefficient piece of equipment you can add to a swimming pool system. Should the sand ever become really dirty, it is easily and inexpensively replaced. In terms of particle size filtered out, sand is the least effective method as it can allow smaller particles to pass back into the pool.

Cartridge Filters

This one is easy to understand. Water passes through a filter material and the filter captures the debris.

This is just like the water filters used under your sink. Cartridges have much more available area to filter than sand. Most start at 100 square feet, and the majority of the cartridge filters sold are larger than 300 square feet so they don’t clog up as quickly and therefore you touch them less frequently. There are two types of cartridge filters in general. In the first case, there are filters elements that are inexpensive to replace and as such, they don’t tend to last as long. Then there are other filters that have very expensive elements and these last 5 or more years.

In both cases, cartridge filters are designed to run at lower pressure than sand. This puts less back-pressure on the pump and hence you get more flow and turnover for an equivalent pump size. Generally, these filters have to be cleaned once or twice a season by simply hosing them off, so you don’t touch them as often. In terms of particle size filtered out, a cartridge is somewhere between sand and DE.

DE Filters

Diatomaceous earth is mined and is the fossilized exoskeletons of tiny diatoms. They are used to coat “grids” in the filter housing and act like tiny sieves to remove debris. They are very small and as such can filter out particles as small as 5 microns.

Diatom filter area is sized between sand and cartridge at around 60 to 70 square feet are most common. Once the filter pressure rises, the filter is backwashed just like a sand filter and then “recharged” with more DE powder. Typically it is poured in a slurry into the skimmer and it then coats the filter grids. DE filters run at higher pressures than cartridge filters and as such can lead to some inefficiency and flow loss.

Now with that background, which swimming filter is best? You can use this question to gauge who you’re talking to in a pool store. Just ask: “Which swimming pool filter is best” and then listen for the answer. There is only one correct answer to that question: can you please define best? If the answer is any of the three, someone is trying to simply sell you something.

  • If you want bulletproof – sand is a great choice.
  • Low maintenance would lead one to a cartridge.
  • The cleanest water might lead you to DE.
  • All three types of swimming pool filters work.
  • You can add a little DE to a sand or cartridge filter to increases its ability to filter small particles.
  • Flocculants can be added to the pool water to create big particles out of small particles (think – flocks of birds are easier to see).
  • Cartridges that become fouled can be replaced.

Go With a High-End Cartridge Filter for Your Pool

Which filter should you choose? Go with a high-end cartridge filter for your pool. The reason is that no one really wants to have another item on the to-do list and good cartridge filter can last a season. Be sure that you:

Barack is an expert pool chemistry guy and experienced online-based pool maintenance assistant via in-depth articles that top search results

How to Select the Correct Filter Size for Your Swimming Pool

How Do I Select the Best Pump for My Pool?

Questions you need to ask before you buy:

  1. How fast of a pump do you need?
  2. How big is your pool?
  3. Is it above-ground or in-ground?
  4. Do you want a hard-wired or plug-in model?
  5. How much horsepower do you need?

Each of these is explained fully below.

Considering Speed When Choosing a Pump

Speed. Pool pumps come with different options of pumping speed: low, medium, and high, which are all necessary when you need to regulate the pumping speed depending on the status of the swimming pool to save on power consumption. Remember:

  • The faster a pool pump, the less power will be used.
  • The slower a pool pump runs, the more the power will be used.
  • They come in single, dual, or variable speeds.

Single Speed

  • These are the most common but have a one-speed (high) setting option.
  • The motor spins the impeller at a single speed depending on the horsepower of the motor and cannot be reduced or increased.
  • Since it will always run at a high speed, it uses a lot of power when it runs full-time and may not be the best choice when you need to cut down on maintenance cost related to power.
  • It is also important to know that single speed pumps have been prohibited in some states, for example, California, mainly to help save on electricity usage.

Dual Speed

  • This pump has two-speed options: low and high. The high-speed is the same as the single speed pump’s, while the low-speed setting adds more flexibility.
  • Dual speed pumps are better than single speed when it comes to power saving, since you can set the pump to run at a low speed at peak usage hours and when the pool isn’t being used often.

Variable Speed

  • These are considered the best since they come with a permanent magnetic motor (PMM), similar to those used in cars, which don’t need electricity to spin the rotor and can be digitally regulated to any speed.
  • These are relatively expensive. However, it may be worth it since the motor produces less friction, making it more efficient, quieter, and longer-lasting than the other kinds of pumps that use induction motors.

I use Hayward SP2602VSP Variable-Speed Pool Pump, which according to my own experience with pool pumps is the best variable speed pump designed with great energy saving Permanent Magnet Motor, which uses a permanent magnet to spin the rotor as opposed to induction motors used in a single or dual speed pool pumps that need extra electric power to induce magnetic field into the rotor to spin it.

In order to ensure optimum results from your pool filter, it’s imperative that your filter be the proper size for your pool. But what is the proper size? When determining the size of pool filter you need, you must take into consideration the volume, flow rate, capacity, and the type of filter you need. Moreover, it needs to fit with the equipment sequence you have. Pool filters are available at Westside Wholesale as cartridge pool filter, sand pool filter , and D.E. pool filter .

To begin determining the best type of pool filter for you, you’ll first need to calculate the volume of water that must be filtered. Your pool volume can be calculated by using some basic mathematical equations. The volume of water in a rectangular pool can be calculated by multiplying length x width x depth. For a round (circular) pool, the volume of water can be calculated by multiplying the radius of the pool by the radius of the pool, by the depth of the pool and then multiplying by Pi (3.14). The volume of water in an oval pool can be determined by multiplying ½ of the length x ½ of the width, x Pi, x depth.

The volume of water in your pool is measured in cubic feet, and your pool filter will need to be able to filter that volume of water.

You will also need to determine the capacity of water that your pool will hold. This is not how much water the pool has in volume, but rather the maximum amount of water it can hold. The standard formula for determining capacity requires that you multiply 7.48 x volume. For example if your pool’s volume is 4,500 cubic feet you would multiply 7.48 x 4,500=33,600. In this case, the capacity of your pool is 33,600 gallons.

You will next need to determine the desired flow rate of your pool. Again, flow rate is determined by using a specific formula, and you will need to know it in order to choose the right pool filter size for your needs. The flow rate may be measured in terms of gallons per minute or gallons per hour. Flow rate is loosely defined as the volume of water in your pool that flows past a specific point during a specified period of time.

For example, in keeping with the example of a pool which has a capacity of 33,600 gallons, consider that you want water to “turn over” or be completely filtered every 12 hours. You would simply divide 33,600 by 12 to get a flow rate of 2,800 gallons per hour (gph). If you wanted to know the gallons per minute (gpm) you would divide the gph by 60. So in this case it would be 2,800 ÷60 = 46.67 gallons per minute. In order to select the best pool filter for your needs, you would need a pool filter that can handle that flow.

The last things you’ll need to determine involves deciding whether you want a sand filter, cartridge filter, or a diatomaceous earth (D.E) filter. You may also want to determine if there is a specific brand that you prefer. Westside Wholesale carries pool filters made by the most reputable manufacturers including Pentair, Hayward, Unicel, Jandy, and Nature 2.

It is always a good idea to select an oversize filter (meaning that it can handle greater volumes of water than you actually need) because this will ensure that your desired filter rate is met, and moreover that more debris is captured. In essence, over sizing your pool filter increases the filter’s efficiency.

A Swimming Pool Chemical Calculator

Common Filter Media Rate
High-Rate Sand: 5 – 20 gpm/ft 2
Cartridge: 0.375 gpm/ft 2
Diatomaceous Earth(DE): 2 gpm/ft 2

It is always recommended to oversize the pool filter. Adequate filtration is the primary source of clean clear pool water. An undersized filter can lead to numerous problems, including cloudy pool water, increased chemical demands, pH swings, and unsafe swimming pool water.

Maximum pump gpm must be used when calculating the minimum required filter area. Exceeding the filter media rate will result in many negative effects to the equipment and poor pool water quality.

RESULTS SHOWN HERE

More About Pool Filter Size and Filter Media Rate

Choosing the right filter:

Each pool filter media has its own unique advantages and disadvantages. Selecting the right one requires consideration of user load, pump max gpm, flow rate, filter media rate, installation location, filter size, maintenance and local code requirements on turn over rate.

An improperly sized filter can lead to cloudy and dirty water. Ensuring the main drain cover is in place, and intact is impossible in cloudy pool water. Being able to visually inspect the main drain cover is important. Not being able to see a swimmer in distress at the bottom because of cloudy pool water is extremely dangerous.

High-Rate Sand Filter Media:

Pool filter sand media is one of the oldest methods of purifying water. Debris, algae, and contaminants get trapped between the sand particles as the pool water passes. High-Rate Sand filters clean particles down to 25-100 micron range. High-Rate sand filter maintenance requires backwashing to clean out the debris and prevent channeling.

Cartridge Filter Media:

Pool cartridge filters clean down to the 10-15 micron range. Replacement and maintenance are easier compared to a sand filter. There is no need for backwashing, cartridge filters are easily removed and cleaned or just replaced. These filters reduce energy cost by the reduced pressure required to operate. Saving on energy and equipment use.

Diatomaceous Earth(DE) Filter Media:

Diatomaceous Earth or DE provides the best filtration at 1-2 microns. DE’s made from fossils called diatoms. Its a fine white powerer that is poured into the skimmer and trapped by a fabric forming a thin layer that traps debris and contaminants but allows water to pass. Maintenance can be tricky and should be handled by a professional for best results.

Maintenance:

Take note of the pressure side psi when first installing the filter. Once the pressure rises over 10 psi past original installation pressure, its time to clean the filter.

Want A Chlorine Free Pool?

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POOL CHEMICAL CALCULATOR APP

Track and chart chemical test history for multiple pools. Save pool equipment configuration. Save operating notes, warranty details and manufacturer support info for each piece of equipment.

If you have a swimming pool filter then the likelihood is that it is a sand filter. As the name suggests a sand filter uses sand to filter the impurities out of the water. Sand is put in the filter vessel and the water is forced under pressure through the bed of sand. The water molecules pass through the gaps between the sand grains but solids in the water are held back in the gaps between the grains.

You cannot use just any old sand in a swimming pool filter it has to be a special refined grade of sand known as 16/30 grade. The numbers refer to the size range of the grains in thousandths of an inch. In 16/30 grade sand the smallest grain will be 16 thousandths of an inch, there should be no grains smaller than this. The largest grain will be 30 thousandths of an inch, there should be no grain bigger than this.

This type of sand is not usually kept in stock in builders merchants or DIY superstores but you can buy it from PoolStore. It comes in 25 kg bags and a typical filter requires 6 or 7 bags. Rather than load them all in your car, we can deliver them to you door the next working day.

How to Select the Correct Filter Size for Your Swimming Pool

It is essential to use the correct sand in your pool filter

If the grains of sand are smaller than 16thou they will pass through the laterals at the base of the filter and end up back in your pool. If you see sand grains in your pool then it is probable that they have come out of the filter either because the grains are too small or because the laterals in the filter are broken.

If the grains are bigger than 30thou they will be too big to catch the fine solids in the water.

After a while the gaps in the sand fill up with dirt from the pool and you have to “backwash” the sand by forcing the water through it in the opposite, upwards, direction. This loosens up the sand allowing the dirt to be washed out and then you can restart the process again.

What Size Heat Pump Do You Need?

Heat pumps are extremely efficient pool heaters. The units themselves do not actually generate heat, but use electricity to distribute it ingeniously. A heat pump can extract heat from cooler air than the water it is going to warm up. This means the operating costs of a heat pump are significantly less than a gas heater. This also means that a heat pump needs to be chosen effectively for its size and energy output to match the pool that needs warming. In this article we will discuss some basic calculations you can do at home to determine what size heat pump is right for you.

The Basics

Before you call your local provider and ask them to send you the heat pump that matches the outcome of the following calculations it is important to discuss your decision with them. They are the experts and they will have experience installing and servicing these units.

It is also worth noting that using a pool cover, at the very least overnight will mean you need a heat pump which is roughly 25% less powerful than what you would need without one.

The quantity of heat and time required to heat a pool is virtually impossible to be accurately calculated due to so many variables. This is because there are other factors at play than those we will discuss below like exposure to sun and wind that can affect the heating demand.

How to Size Your Heat Pump

Determine the Volume of Your Pool

To determine the volume of your pool measure the surface area and then multiply that by the average depth. For example, a rectangular 3 x 5 metre pool with an average depth of 1.4 metres has a volume of 21 cubic metres. There are 1000 litres in a cubic metre, so the volume of our example pool is 21,000L.

Apply a Conversion Factor

Divide your pool volume by 2500. In the case of our above example that would generate 8.4. This is the number of kW required for your pool heat pump. Typically, heat pumps only come at specific power ratings, so choose the next one larger than 8.4kw.

Other Factors

The above conversion factor is based upon common requirements for New South Wales. It is the calculated power required when using a pool cover. Using a heat pump without a pool cover is like driving with the windows down while using air conditioning.

The other factors of this calculation are based upon personal preference. The biggest factor for deciding a heat pump is the difference between the coldest average air temperatures you will want your pool to be usable at and the desired heating temperature of the pool. This is referred to as the heat gain requirement.

Use an Online Calculator to Test Your Specifics

There are online macro calculators that will determine specific power requirements for your pool based upon individual measurements and requirements including your local temperature range.

Call Australian Energy Systems for More Information

Australian Energy Systems have been installing and servicing pool heaters across New South Wales and Queensland in commercial and residential pools for more than twenty years. They know everything worth knowing about heat pumps and if you’d like to discuss how a heat pump could work for you call 1800 243 847 or get in touch online.

There are three common pool filter types – sand, cartridge and Diatomaceous Earth (D.E.). All three of these pool filter types will keep your pool and spa clean, but you should consider the needs of your specific application, your other equipment and plumbing size before making a selection.

When choosing a filter type and size, we recommend enlisting the help of a pool professional to ensure the proper products are selected for your pool. Our pool pros will take into consideration the weather conditions in your area, the types of debris that can land in your pool, and they will also evaluate your entire application – how many gallons your pool has, your plumbing size and the needs of and types of other pool equipment you have.

Tip: An undersized pool filter will render it ineffective and lessen its life; the larger the filter, the longer the time between cleanings.

Pool System Plumbing

The first thing you want to check is the pool system plumbing. For instance, the maximum flow rate through a 1.5 inch PVC pipe is 44 gallons per minute (GPM). Even if you have a pump that can move 100 GPM, it won’t do you much good if the piping will only allow 44 GPM through it. An oversized pump not only wastes energy and money, but it may damage other equipment in the process.

The Right Filter

The correct filter size depends on the size of the pool. To maintain good water clarity, you must run the pump long enough each day to filter and sanitize the water in your pool. All filters have a GPM design rating and a turnover rate. A turnover rate of 8 or 10 hours is a typical sizing rate for residential pools.

All filters have flow requirements. D.E. filters are normally rated at 2 GPM per square feet (sq. ft.) of filter area for maximum flow. This means a 48 sq. ft. D.E. filter will have a maximum flow rate of 96 GPM, and a 60 sq. ft. model will be rated at 120 GPM. So if you have a pump that is going to flow 100 GPM, you would need to go to the 60 sq. ft. D.E. filter.

For a sand filter, it is best to look at the flow requirements of each filter as they can vary from 15 GPM per sq. ft. and higher. Just make sure the filter you choose can handle the flow rates needed.

Cartridge filters are becoming increasingly popular due to their eco-friendly operation. These filters don’t need to be backwashed and can save thousands of gallons of water each season. You should always adhere to the manufacture’s maximum flow rates and be sure not to size a cartridge filter too small as that may cause short cleaning cycles. The best way to determine flow rates for cartridge filters is to use the formula of 3x the flow rate for minimum, and the manufacture’s rating for maximum. The larger the cartridge filter, the longer the cycles between cleaning becomes.

How to Select the Correct Filter Size for Your Swimming PoolWhy Work with A Pool Professional?

This is quite a bit of information to digest and your best bet is to talk to a pool professional to ensure you are using the appropriate products for your investment. With the help of a pool professional, you can be well on your way to receiving the best water clarity and to using the most efficient products in terms of energy use and water conservation.

Remember: Installing a filter too small for the output of the pump could cause costly damage to your filter.

Need some help locating a pool professional near you? Check out our dealer and servicer locator.

Filter Sizing

Once you have chosen the right type of filter for your pool, it is important to get it sized properly. It must be sized to match the pump which in turn must match the circulation needs of the pool. If the filter is undersized, it will fill up quickly and also can be damaged by the force of the pump. If the filter is undersized, it may not backwash well.

It is important to keep in mind that the manufacturer’s flow ratings for filters are often very optimistic. Our experience suggests that the following guidelines are much more realistic.

Filter Sizing Chart #1

Optimal Square Footage of Filter for Different Pump Sizes
Pump Size Flow Rate Sand Filter DE Filter Cartridge Filter
3/4 HP 40 2.7 24 100
1.0 HP 50 3.4 36 150-200
1.5 HP 65 4.3 48 300
2.0 HP 87 5.8 60 400
2.5 HP 105 7.0 72 500
3.0 HP 120 8.0 84 600
Maximum Flow Rate Through Filter Media (flow per square foot of filter media)
Filter Type Sand Filter DE Filter Cartridge Filter
Maximum Flow Rate 15 GPM/sq. ft 2.0 GPM/sq. ft 0.25 GPM/sq. ft

Filter Sizing Chart #2

Intake Lines (minimum)

Recommended

Filter Size

Cartridge – 100-200 Sq. Ft.

2 – 1.5″ or 1 – 2.0″

Cartridge – 300-400 Sq. Ft.

2 – 1.5″ or 1 – 2.0″

Cartridge – 400-500 Sq. Ft.

Cartridge – 500+ Sq. Ft.

Note that these recommendations are only approximations based on typical conditions.

On-site analysis must be done to insure that the filter matches up properly with the pump and the pool. For instance, if the plumbing runs on the equipment are particularly long, then the resistance to flow in the piping will be greater and intake lines may need to be larger than specified in this chart.

Note also that this may differ from the recommendations listed by the manufacturer .

The literature may indicate that it is OK to match up a 2.5 or 3.0 hp pump to a 60 square foot DE filter, but we never recommend it because we have seen plenty of DE filter grids blown out by these larger sized pumps. It is always better to oversize the filter. With an oversized filter, the water flows through the filter media at a slower velocity and that results in finer filtration and longer filter cycles.

Some builders will install a 3.0 hp filter pump on a pool/spa combination in order to give maximum water flow through the spa jets.

This is nice except for the fact that the pump is so powerful that it has the potential to damage the grids in the filter. The better way is to install a smaller filtration pump for the pool and then run a separate booster pump. This keeps you from having to run a large 3.0 hp pump every day on the normal filter cycles.

Choose Wisely, Save Money and Turn Your Blue Swimming Pool Green

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How to Select the Correct Filter Size for Your Swimming Pool

No one likes to walk out in his or her yard and find a green swimming pool — or do they? In this instance, we’re not talking about literally letting your swimming pool water turn green. Instead, we are talking about creating an enticing pool that is easy on the environment and on your budget, as well. Armed with just a little information, you can save money on your monthly utility bill, streamline your pool maintenance, and your swimming pool water will never look better!

However, before we start the transformation there are a few terms and concepts to understand. The overall goal of the pool circulation system is to cycle the water through the pool filter system, where dirt and debris are removed and water is sanitized and returned to the pool, clean and inviting. The heart of the system is the pool pump. An American National Standard, ANSI/APSP-5 Standard for Residential In-ground Pools, provides guidelines for maintaining proper water cleanliness. In it, we find that a “turnover” is the amount of time it takes to move a volume of water, equal to the size of your pool, through the filtration and sanitation process once.

How Much Pump Do I Need?

If your pool volume is 15,000 gallons, then one turnover would be equal to 15,000 gallons. This turnover is required every 12 hours, or twice a day. Pumps, on the other hand, use a slightly different description of “gallons per minute” or GPM. Think of this a little like the miles per gallon (MPG) quoted as gas mileage on your car. Our goal is to meet or exceed our minimum required turnover and to use the least amount of energy doing it.

Here is the problem: most pools are designed to sell, not to operate. It has become very popular to “sell on horsepower” or how powerful a swimming pool water pump is, not how efficiently it operates. Many pool builders routinely sell against their competition by quoting a “bigger” pump as a “free upgrade.” As a result, the vast majority of pools have pumps that are severely oversized. Water pumps of 1, 1.5, and 2 horsepower are very common — and for the average size pool, very oversized.

Oversizing pumps have become such an issue that the State of California (a big pool state), recently enacted a law to control how big of a pump could be placed in a swimming pool. While it might not seem possible, it’s actually less expensive to run your pool water pump 24/7 if you have the correct pump in place. Unless you have a two-speed, or variable-speed pump, chances are you cannot operate around the clock. The savings with one of these pumps can be so large, you might want to invest in one, and you certainly want to consider if it is time for a replacement. One other key advantage of these pumps — you can’t hear them. Not only will you save money, but when they operate, they simply don’t make any noise.

Calculating Your Swimming Pool Water Pump Needs

Now it’s time for a little arithmetic. Get out your calculator to figure out what you need to properly circulate your pool water and squeeze out the most efficiency. Using the example below, substitute your pool’s volume and do the math:

Remember: Pool Volume (gallons) × 2 = gallons required daily for a 12-hour turn

Example:

  • We have a pool that holds 15,000 gallons of water.
  • 15,000 gallons × 2 turnovers/day = 30,000 gallons/day
  • We need to circulate 30,000 gallons of water every 24 hours – but remember, a pump has specifications of Gallons Per Minute (GPM)

Now convert that to GPM:

  • 30,000 gallons ÷ 24 hours = 1250 gallons/hour
  • 1250 gallons/hour ÷ 60 minutes = 20.8 gallons/minute (GPM)

A 15,000-gallon pool needs about 20 GPM output if we want to run it 24 hours per day.

Most people run their pool on an 8-hour on/16-hour off (stagnant) cycle. That means for the majority of the day, the pool water is just sitting there, not circulating. It is during this stagnant period that bad things happen:

  • Algae outbreaks
  • Debris build-up
  • pH swings

Not only will running your pool around the clock cost less, but it will also be much easier to maintain. The reason is that you will no longer let the pool sit idle, where it drifts out of that “perfect pool water” condition. This makes you think back to that 2 HP upgraded pump you received when building your pool. Perhaps it wasn’t such a good deal, after all!

If you are in the market for a swimming pool, keep this in mind when evaluating proposals. The most important factor for any pool water pump is not how much it costs to buy it — it is how much will it cost to own and operate. The best choice will be to upgrade to a multi/variable-speed pump. It is good for your budget and it is good for the environment.

Trying to learn how to size a pool heat pump?

In this post, we show you how

(Of course, if you’re in a hurry, why not use our pool heater sizing calculator?)

If you landed on this page, then chances are you’re thinking about installing a heat pump. From unmatched energy efficiency to the ability to heat your pool with, or without the sun — there are countless benefits to heat pump pool heaters.

Of course, to get the most out of your heat pump, it’s important that choose one suited to the conditions you’ll be using it in. Doing so ensures that you get the most consistent and cost-effective performance out of your heater.

It needs to be the right size.

But don’t worry, there are only a few simple things to consider beforehand. And in this post, we go everywhere everything you need to know to size a pool heat pump for your swimming pool.

So let’s just jump right into it

What to consider

Size of your pool

How to Select the Correct Filter Size for Your Swimming Pool

The size of your pool is one the most important things to keep in mind when sizing a pool heater. And this is because the amount of water a heat pump needs to heat (the size of your pool) directly correlates to how powerful it needs to be.

So by that logic, the bigger your pool (volume), the stronger/bigger your heat pump should be. When you size a pool heat pump, you need the surface area of your pool, which is easy to find and explained later in this post.

That said, although pool size is important, it’s not the only factor to consider.

Where you live (climate)

How to Select the Correct Filter Size for Your Swimming Pool

Equally important as the size of your pool, is where you live. Specifically, the climate.

If you live in a climate that’s mostly warm year round, then most of the time, your pool heat pump won’t have to work all that hard. For someone with an average sized pool, using a smaller to standard sized pool heat pump would be ideal.

On the flip side, for pool owners living up north or in more diverse climates, it’s a little bit different. If your pool has to brave all 4 seasons, then it’s important to know how cold it can get during the swim season.

This is because of the way pool heat pumps work. Since they harvest the natural heat in the air, they tend to perform best in warmer climates.

But a heat pump can still do its job even in cold weather. It just has less starting heat to work with, so to compensate, it works a bit harder. In fact, heat pumps like the Oasis Platinum are designed to run all the way down to outside temperatures in the 30s — most other heat pumps usually cut off around the 50-degree mark.

In fact, heat pumps like the Oasis Platinum are designed to run all the way down to temperatures in the 30s — most other heat pumps usually cut off around the 50-degree mark. Pool heat pumps with advanced low-temperature performance, like the Oasis Platinum, can help pool owners in colder climates stretch out their pool season even longer.

The third factor

So with your location and pool size in mind, what’s left to consider?

Your swimming habits.

Do they factor into the actual calculations needed to size a heat pump? Not really.

But if you’re someone who’s in the pool almost every other day, then heating speed may be important to you.

Well, with a stronger pool heat pump comes stronger heating ability. So even if you’re already in a fairly warm climate, it can sometimes make sense to choose a stronger unit if you’re in the pool often and have the extra room in your budget.

Of course, pool heat pumps by nature are designed to provide resilient, and reliable heating in a full range of climates. So even with a standard sized heat pump, you can’t go wrong.

And on that note, let’s get to what you came here for.

How to size a pool heat pump | What size pool heater do I need

You may not realize it, but you’re already halfway done. Yup, with your pool size and location in mind, you have 60% of the information you need to size a pool heat pump.

Of course, for the sake of accuracy, you’ll still need to do a little math. But don’t worry, it’s a really simple formula.

[Want to skip the math and size your heat pump faster? Use our heat pump sizing calculator]

How To Size A Pool Heat Pump

How to Select the Correct Filter Size for Your Swimming Pool

1.) Determine the hottest temperature you want to heat your water up to. This is your target temperature

Ex.) A target temperature of 80 degrees

2.) Find the average temperature of the coldest month of the year for the area you live in

Ex.) If you live in Florida, the coldest average temperature during swim season may be 60 degrees

3.) Subtract the coldest average temperature from the target temperature

Ex.) 80 degrees (target temperature) – 60 degrees (coldest average temperature) = 20

20 degrees is your Temperature Increase number

4.) Calculate the size of your pool/surface area

Use this formula to calculate your pool’s surface area: Width x Length = Surface Area

Ex.) 15ft x 30ft = 450 sq ft (Surface Area/Pool size)

5.) Calculate the amount of heating power (BTUs) needed to heat your pool

You already have all the numbers you need, so here’s the formula:

Pool Surface Area x Temperature Increase x 12 = BTUs needed

Ex.) 450 x 20 x 12 = 108,000 BTUs

According to the above example, a heat pump size of at least 108,000 BTUs or more would be a good choice.

Closing thoughts

So now that you know how to size a pool heat pump, the next step is taking action and getting yours installed.

But if you aren’t quite there yet and still want to learn more, start here:

Trying to learn how to size a pool heat pump?

In this post, we show you how

(Of course, if you’re in a hurry, why not use our pool heater sizing calculator?)

If you landed on this page, then chances are you’re thinking about installing a heat pump. From unmatched energy efficiency to the ability to heat your pool with, or without the sun — there are countless benefits to heat pump pool heaters.

Of course, to get the most out of your heat pump, it’s important that choose one suited to the conditions you’ll be using it in. Doing so ensures that you get the most consistent and cost-effective performance out of your heater.

It needs to be the right size.

But don’t worry, there are only a few simple things to consider beforehand. And in this post, we go everywhere everything you need to know to size a pool heat pump for your swimming pool.

So let’s just jump right into it

What to consider

Size of your pool

How to Select the Correct Filter Size for Your Swimming Pool

The size of your pool is one the most important things to keep in mind when sizing a pool heater. And this is because the amount of water a heat pump needs to heat (the size of your pool) directly correlates to how powerful it needs to be.

So by that logic, the bigger your pool (volume), the stronger/bigger your heat pump should be. When you size a pool heat pump, you need the surface area of your pool, which is easy to find and explained later in this post.

That said, although pool size is important, it’s not the only factor to consider.

Where you live (climate)

How to Select the Correct Filter Size for Your Swimming Pool

Equally important as the size of your pool, is where you live. Specifically, the climate.

If you live in a climate that’s mostly warm year round, then most of the time, your pool heat pump won’t have to work all that hard. For someone with an average sized pool, using a smaller to standard sized pool heat pump would be ideal.

On the flip side, for pool owners living up north or in more diverse climates, it’s a little bit different. If your pool has to brave all 4 seasons, then it’s important to know how cold it can get during the swim season.

This is because of the way pool heat pumps work. Since they harvest the natural heat in the air, they tend to perform best in warmer climates.

But a heat pump can still do its job even in cold weather. It just has less starting heat to work with, so to compensate, it works a bit harder. In fact, heat pumps like the Oasis Platinum are designed to run all the way down to outside temperatures in the 30s — most other heat pumps usually cut off around the 50-degree mark.

In fact, heat pumps like the Oasis Platinum are designed to run all the way down to temperatures in the 30s — most other heat pumps usually cut off around the 50-degree mark. Pool heat pumps with advanced low-temperature performance, like the Oasis Platinum, can help pool owners in colder climates stretch out their pool season even longer.

The third factor

So with your location and pool size in mind, what’s left to consider?

Your swimming habits.

Do they factor into the actual calculations needed to size a heat pump? Not really.

But if you’re someone who’s in the pool almost every other day, then heating speed may be important to you.

Well, with a stronger pool heat pump comes stronger heating ability. So even if you’re already in a fairly warm climate, it can sometimes make sense to choose a stronger unit if you’re in the pool often and have the extra room in your budget.

Of course, pool heat pumps by nature are designed to provide resilient, and reliable heating in a full range of climates. So even with a standard sized heat pump, you can’t go wrong.

And on that note, let’s get to what you came here for.

How to size a pool heat pump | What size pool heater do I need

You may not realize it, but you’re already halfway done. Yup, with your pool size and location in mind, you have 60% of the information you need to size a pool heat pump.

Of course, for the sake of accuracy, you’ll still need to do a little math. But don’t worry, it’s a really simple formula.

[Want to skip the math and size your heat pump faster? Use our heat pump sizing calculator]

How To Size A Pool Heat Pump

How to Select the Correct Filter Size for Your Swimming Pool

1.) Determine the hottest temperature you want to heat your water up to. This is your target temperature

Ex.) A target temperature of 80 degrees

2.) Find the average temperature of the coldest month of the year for the area you live in

Ex.) If you live in Florida, the coldest average temperature during swim season may be 60 degrees

3.) Subtract the coldest average temperature from the target temperature

Ex.) 80 degrees (target temperature) – 60 degrees (coldest average temperature) = 20

20 degrees is your Temperature Increase number

4.) Calculate the size of your pool/surface area

Use this formula to calculate your pool’s surface area: Width x Length = Surface Area

Ex.) 15ft x 30ft = 450 sq ft (Surface Area/Pool size)

5.) Calculate the amount of heating power (BTUs) needed to heat your pool

You already have all the numbers you need, so here’s the formula:

Pool Surface Area x Temperature Increase x 12 = BTUs needed

Ex.) 450 x 20 x 12 = 108,000 BTUs

According to the above example, a heat pump size of at least 108,000 BTUs or more would be a good choice.

Closing thoughts

So now that you know how to size a pool heat pump, the next step is taking action and getting yours installed.

But if you aren’t quite there yet and still want to learn more, start here:

How to Select the Correct Filter Size for Your Swimming Pool

How to Select the Correct Filter Size for Your Swimming Pool

The only way to really take advantage of your pool, both during the day and at night, is by installing colorful and soothing lights all around. All pool owners will have to choose between halogen, fiber optic or LED pool lights. Let’s see which pool lights are best for you and your significant other.

Note: Pool lights are one of the more expensive purchases you’re going to make when it comes to your pool accessories. They are also very tough to switch. Do not rush this decision.

Halogen Pool Lights

Get up to 4 Free Quotes!

Halogen lights used to be the most popular pool lights, but as times have evolved, so have available pool lights. Halogen lights can be installed in above ground and inground pools. Just like some of the other options discussed, they are affordable and can easily light up your entire pool (or not if you are setting the mood).

The biggest drawback of halogen lights is their efficiency. They are not energy efficient and LED lights are said to use about 80% less energy than halogen lights. Additionally, you will have limited options when it comes to colors.

Another great addition is a new hot tub. See some of our favorite additions at Hot Tub and Spa Accessories.

LED Pool Lights

LED lights are the most popular lighting option today. They shine bright, have plenty of colors, are durable and perhaps most importantly, they are energy efficient. As I said above, they use about 80% less energy than other pool lights.

LED lights can be added to either pool type and are popular with floating pool lights for above ground pools. They are very bright and depending on your pool size, you may only need one LED light. The same can’t be said for halogen or fiber optic lights.

When compared to fiber optic lights, LED pool lights are much cheaper and according to Swimming Pool Supplies, they can last anywhere from seven to 15 years.

A fallback comes when you have to change the bulbs. You will have to remove the sealed housing unit and take it above water. The entire process for changing the bulb could take up to 30 minutes. Some homeowners may have an issue holding lights within a pool and if so, you should contact a pool contractor in your area.

Fiber Optic Pool Lights

Get up to 4 Free Quotes!

We have come to the Grand Poobah of pool lights that can set the mood or enhance your swimming experience. Fiber optic lights come a wide array of colors and can be easily installed under water, around your pool or within a waterfall. Perhaps the greatest advantage of fiber optic lights is the simplicity in replacing them. They are frequently placed above the pool in a dry box. All you have to do is open the box and change the bulb. It’s much faster than changing LED bulbs.

When it comes to cost and durability, LED wins out. Fiber optic lights require a hefty fan to cool the bulb down. This comes with an extra cost. Also, compared to the 15-year lifespan of an LED light, fiber optic lights rarely make it past seven.

Conclusion

Pool lights may be one the more expensive pool items you purchase, but they can have the greatest effect in your swimming experience. Whether you want to take a dip at night or set a romantic evening with your significant other, pool lights is one decision you should never overlook.

If you are thinking of adding a romantic touch to your home, see what it cost to install a swimming pool.

Choosing the right Pool Pump will ensure you consistently have a clean and inviting pool with low operating and maintenance costs as well as minimum inconveniences that you and your family will enjoy every day.

A poorly chosen pump will not only perform deficiently and create issues with the pool filtration but it can have detrimental effects on all the pool equipment that would only be seen in the long term. It is important to spend time analyzing the pool configuration and the requirements in order to make the right choice.

Let us know some details about your pool, and one of our qualified pool technicians will get back to you with our recommendations for a pool pump.

If you buy from us a Pool Pump that we recommended and you find that you are not happy with its performance, you can contact us within 30 days of the purchase date and we would arrange to pick it up from you anywhere in Australia and give you a full refund.

We value your privacy. Your details will be used only to reply with our recommendation.

Our advice is not theoretical, it is based on thousands of hours of real experience supplying and servicing thousands of pools in Australia.

Pool & Spa Warehouse is Australia’s largest and fastest growing independent Pool & Spa Equipment and Supplies Retailer. We service over 140,000 customer a year through our 7 super stores and have a proven track record of excellence in the industry.

There are a few primary factors that go into finding the right size pool pump. Below, we’ll run through how to easily figure it out step-by-step and choose your pool pump confidently.

How to Figure Out What Pool Pump Size You Need

  • Calculate the volume of your pool
  • Calculate minimum flow rate
  • Determine maximum flow rate
  • Determine your flow rate range
  • Add in Total Dynamic Head (TDH)
  • Settle on your final specs

Pool Volume

First up, you need to figure out how many gallons of water are in your swimming pool. This calculation differs based on pool shape, but is pretty straightforward. Use our pool volume calculator below and then we’ll start calculating the minimum flow rate you need for your pump.

All good? Okay, let’s move on to the next step.

Minimum Flow Rate

Once you have the approximate number of gallons of water in your pool, we have to figure our minimum flow rate for the pump, using a Gallons Per Minute (GPM) calculation. GPM takes into account your pool size and the number of “turnovers” you need per day (your turnover rate). For both traditional chlorine pools and saltwater pools, the industry standard is 2 turnovers per day.

Before we get into the calculation, you have a few options here. You can choose to run your pump 24 hours per day (decreasing your GPM needs) or twice a day in different segments. The typical two-a-day segments are: 6 hour cycles, 8 hour cycles, and 10 hour cycles. So, let’s calculate the minimum flow rate we need for all four of these options.

The ultimate goal is efficiency here – balancing electricity bill savings with pump horsepower and balanced water chemistry. Running at low horsepower for longer periods of time results in a more balanced water chemistry, but can be a sink on your electricity bill. The opposite is true for higher horsepower and shorter run times.

This is where variable speed pool pumps come in handy – they can speed up and slow down when you need them to, resulting in a much safer pool chemistry and energy efficient setup, which is a nice savings on that electric bill.

Okay, let’s move on to the next part of our pool pump sizing – figuring out your maximum flow rate.

Maximum Flow Rate

Fortunately, you don’t have to do a bunch of fancy math to figure our maximum flow rate. It is completely dependent on your plumbing system and other pool equipment, all of which should have documentation on maximum flow rates. We’ll start with filters.

Filters

There are three types of pool filters (sand, cartridge, and DE) and all of them have different maximum flow rates based on their surface area. Make sure you stay below the maximum flow rates for your filter system or you could end up damaging it. Here are the flow rates for common filter types and sizes.

Sand Filters

As a general rule of thumb, sand filters typically fall between 19-22 Max GPM per square foot of surface area.

  • 1.8 square feet surface area = 40 GPM
  • 2.3 square feet surface area = 50 GPM
  • 3.1 square feet surface area = 60 GPM
  • 4.9 square feet surface area = 100 GPM
Cartridge Filters

Cartridge filters are a lot bigger and a little less exact. Typically, you’re going to average 0.3 to 0.35 GPM per square foot of surface area.

  • 100 square feet surface area = 32-38 GPM
  • 200 square feet surface area = 55-75 GPM
  • 300 square feet surface area = 80-112 GPM
  • 400 square feet surface area = 100-150 GPM
DE Filters

DE filters are a little rangy as well. Plan for approximately 1.75 GPM per square foot of surface area, assuming the middle of the ranges below.

  • 24 square feet surface area = 36-48 GPM
  • 36 square feet surface area = 54-72 GPM
  • 48 square feet surface area = 72-96 GPM
  • 60 square feet surface area = 90-120 GPM

Now that we have filters settled, let’s move on to maximum flow rates for plumbing.

Plumbing

You never want to put more pressure in your pipes than they can handle. The maximum flow rate of your plumbing setup depends on the pipe size and should be clearly labeled on your system. If not, you can use these common values or ask your contractor.

  • 1.5″ pipes = 43 GPM
  • 2″ pipes = 73 GPM
  • 2.5″ pipes = 120 GPM

Heads up: your plumbing setup may be different across your entire pool environment. For example, the pipes leading to your spa could differ from the main pool area. Always remember to take the lowest of the maximum flow rates for sizing up your pool pump. Otherwise, you could risk damaging the setup for part of your pool environment.

Min and Max Flow Rate Range

Almost there! Now that we have the minimum and maximum flow rates for your pool setup, put them together to get to your flow rate range: one of the two main specs for determining the pool pump size you need.

So, let’s say you have a 15,000 gallon inground pool. With two turnovers per day, your minimum flow rate comes to 20.8 GPM.

Let’s also say that you have a 2.3 square foot sand filter (50 GPM max) and 1.5″ plumbing (43 GPM). You have to take the lower of those two values to make sure you don’t overwork any components of your pool, so your maximum flow rate comes to 43 GPM.

In this example, our flow rate range comes out to 20.8-43 GPM.

Let’s figure out the last main spec you need for your pool pump: total dynamic head.

Total Dynamic Head (TDH)

Total dynamic head is a resistance metric – it tells you the total amount of resistance in the hydraulic system of your pool. The filter, pump, pipes, heater, backwash valve, return, and other accessories have an effect on how water flows throughout your system. Most inground pools will be somewhere around 50 TDH. Above ground pools typically fall around 30 TDH. We’ll go into more specifics on TDH in another post.

Final Specs

Okay, we now have everything we need! All pool pump models will have charts with horsepower estimates based on flow rate ranges and total dynamic head. In our inground pool example, we need a pool pump with a 20.8-43 GPM flow rate range and 50 TDH (also called Feet of Head).

There you have it! Be sure to check out our recommendations for the best single and variable speed pumps as well.

Questions? Shoot us a message and we’ll be happy to help.

How to Select the Correct Filter Size for Your Swimming Pool

There’s no way around it: every pool should have a cover.

Some pool owners get by without one, but I can assure you they’re spending way more time and money opening, winterizing and maintaining them than people with covers.

So, yeah: it’s definitely a good idea to invest in a high-quality cover that will last you years to come!

4 reasons why you need a pool cover

There are several reasons why pool covers are a great idea, but among the best is that it will make your life a whole lot easier!

1. For safety

Some swimming pool covers are designed specifically to serve as safety barriers for people or animals who happen to fall in, and are usually made of sturdy mesh and each one has its own weight limits; the higher the weight limit, usually the heavier the cover.

These mesh covers are usually installed with a roller of some type to roll them up either manually or electronically.

2. To save energy

According to Energy.gov, a pool cover is the “single most effective means of reducing pool heating costs.”

About 70% of energy is lost through evaporation and pool covers minimize evaporation. How?

Let’s go back to 6th grade science. Remember when you did those cool experiments that demonstrated how evaporation works? Here’s a refresher:

Evaporation is basically when a liquid substance becomes a gas. And it does this when it is heated. The molecules then move so rapidly that they “escape into the atmosphere as molecules of water vapor.”

How quickly the water evaporates depends on some other factors, too, like wind, temperatures, and humidity but the average pool loses about 25,000 – 50,000 gallons of water per year this way.

That means you’ll have to add more water to keep your pool full, which means your pool heater will have to work harder and longer to heat up the fresh water.

Pool covers also keep heat in the pool and serve to kind of keep your water warming even after you turn the heater off. And solar covers go a step further by collecting the heat of the sun and directing it into the water to warm it naturally.

All these factors help save energy by heating your pool naturally and preventing you from having to add as much new water each week.

3. To reduce chemical use

The most common pool chemical you probably use is chlorine. The problem with chlorine is that it deteriorates under UV rays.

A pool cover will obviously help protect the water from the sun when the pool is not in use, cutting down on the amount of chlorine you need to add each week.

4. To keep it clean

This may be a no-brainer, but keeping your pool covered keeps out unwanted debris. A lot of pool owners don’t think much of this because they simply skim leaves and bugs out of their pools every morning.

But what about the things you can’t see that cling to the bottom and sides of the pool surface like algae spores and dirt?

Keeping a cover on it helps cut back on these unhealthy pool invaders. This also means less scrubbing and vacuuming for you.

Types of inground covers

Now that you understand why a pool cover is so important, let’s go over the different types.

There are basically four types of pool covers:

  • Solar covers
  • Security covers
  • Standard winter covers
  • Automatic covers

Let’s check out the pros and cons of each one.

Solar covers

How to Select the Correct Filter Size for Your Swimming Pool

If you’re interested in heating your pool efficiently and cheaply, then a solar pool cover (aka bubble cover) is the way to go.

How to Choose the Correct Size Heat Pump or Heater for Pool and Spa

Pool heater sizing is measured in BTU’s (British Thermal Units.) The higher the number of BTU’s, the quicker you can heat your pool water. To find out how many BTU’s are required for your specific application, you must calculate the surface area of your pool; your geographic location; ambient temperature; and the environmental conditions such as shade or wind. Whether you retain heat with a solar cover, also determines sizing requirements.

Many factors depend on how you heat your swimming pool – installation costs, how often you use your pool, size, location and climate. This guide will show you how to calculate the minimum heating capacity for your pool based on your specific application and provide you with the information you need to make an informed decision on the best and most economical way to heat your pool.

Important Reminder:

A pool heater can never be too big, but buy a pool heater that isn’t big enough and you’ll never be satisfied.

When selecting your pool heater, always choose a heater rated somewhat higher than your actual pool surface area and desired temperature rise required. There is no such thing as “oversizing” a pool heater. The larger the BTU output of the pool heater you buy, the quicker it will heat your pool water. This means less run time on the heater and a longer overall heater life span. You will always be glad you opted for the larger pool heater.

A pool will gradually lose heat due to evaporation and may cause your pool to take longer to achieve desired temperature. Investing in a pool cover will reduce heat loss by up to 80 percent.

Step 1 Determine Ideal Water Temperature

How warm do you want the pool water and how fast do you want to raise the temperature? Most pool owners consider 75 – 85 degrees Fahrenheit to be adequately comfortable.

Step 2 Determine Average Ambient Temperatures

Calculate the average temperature in your area during the coldest month you intend to use it.

Important: Consider other weather conditions, including humidity, wind chill, and night temperatures. If you live in a dry climate, if wind speeds are high or temperatures drop at night, you should plan for a larger heater.

Step 3 Temperature Rise

Subtract the average temperature from your ideal temperature. The result is the number of degrees your heater will need to heat a pool in order to make it comfortable.

Step 4 Measure Pool Capacity

Find the surface area of your pool in square feet. Note the length, width, depth, gallons and shape.

Step 5 Choose a Heating Condition

Decide how you plan to use your pool and how often. There are two heating conditions to choose from; heat from cold or maintain the desired temperature. If pool use will be on a daily basis, you may wish to keep it heated continuously. Heating from cold will require raising the water from cold to the desired temperature.

Multiply the pools surface area in feet by the Temperature derived in Step 3. Then multiply that figure by eleven. The result is the approximate BTU/hr. (British Thermal Units per hour) the heater requires in order to heat your pool properly.

Important: A pool will gradually lose heat due to evaporation and may cause your pool to take longer to achieve desired temperature. Investing in a pool cover will reduce heat loss by up to 80 percent.

Step 6 Choose a Heater Type

There are a variety of pool heating methods available in a full range of capacities and models. Poolheatpumps.com carries heat pumps, gas pool heaters, propane pool heaters, electric spa heaters and solar pool heaters to help make your pool water temperature comfortable any time of year. Remember that a higher capacity heater will be more efficient and use less energy to heat your pool.

Let a pool heating professional do the work.

A trained pool heating professional can perform a proper sizing analysis for your swimming pool to determine the correct pool heater size that you need. We’ll provide you with product features and details on our complete line of heat pumps and heaters. If you have questions, please feel free to call us at 1-800-741-9956. Our team of friendly pool experts will answer any questions you may have and offer technical advice in selecting the model that is right for your pool.

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How to Select the Correct Filter Size for Your Swimming Pool

Choosing the correct pool pump can seem like a daunting task. Consumers are faced with new terms like “flow rate” and “head pressure” and have no real idea how to figure these rates. Using a few simple calculations, consumers can get a good idea of what pump will suit them best.

How to Select the Correct Filter Size for Your Swimming PoolMan with hands on his hips

The first calculation that needs to be figured is called flow rate. This tells the amount of water that can be moved within a certain time period and is usually measured in gallons per minute (gpm). To figure this, consumers first have to know how many gallons of water are in their pool.

To figure the gallons in the pool, first multiply the length and width of the pool by the depth. For example, for a pool that is 10 feet (3.0 meters) wide and 20 feet (6.1 meters) long and 5 feet (1.5 meters) deep, multiply 10 times 20 times 5 to get a total of 1000 cubic feet (28.3 cubic meters). There are about 7.5 gallons (28.4 liters) in one cubic foot of space, so now multiply 7.5 by 1000. The swimming pool in this example has approximately 7,500 gallons (28,390 liters).

The average pool needs to circulate the equivalent of all of the water in the pool about every four to six hours at least once or twice a day. This does not mean that all the water will be circulated, but it ensures that a large portion of it will be. To figure out the flow rate, the user must decide how often they want the water to fully circulate.

For example, for the 7,500 gallon (28,390 liter) pool explained above, a consumer decides they would like the pool to fully circulate every six hours. Divide the total gallons by six. That means there are 1,250 gallons (4,731 liters) per hour that need to circulate. Divide that number by 60, the number of minutes in an hour, to find the gpm. For the example here, the flow rate would be right around 20 gpm.

Some will stop here and assume that they simply need a pool pump with a flow rate of 20gpm. This calculation does not take into account the resistance to flow that occurs from the drag created within piping and through filtration systems. This resistance is called head pressure. It is calculated in feet of head.

To determine the exact head pressure is a difficult and mathematically challenging task. Instead, pool owners can use a quick at-home estimation. First, figure out how many feet of piping there is between the pump and the area where water is put back into the pool. This is the initial pressure and the starting figure for head pressure.

Now, if a filter is used to draw and return water, divide the number in half since that assistance will lessen the difficulty of transporting water. For any areas where the diameter of the return line is changed at, add a number equal to the percentage of change. For example, if using a 1 inch (2.54 cm) pipe for 10 feet (3 meters) that changes to 3/4 inch (1.9 cm) pipe, add 25% more, or 2.5 feet (.7 meters), to the calculation.

Every 90 degree turn adds another one to two feet of head. Any inline filters will add two to ten feet of head. If the filter uses a course material, estimate on the lower end. The finer the filter type, the more feet added.

If the water is returned at the water surface of the pool or above, that is the end of calculations. If it is below the surface, add one feet of head for each foot under the surface. Generally, an in-ground pool will have 50-60 feet of head pressure, while an above ground will have around 30 feet of head pressure.

After the head loss has been calculated in feet, check the manufacturer’s charts to see what pool pump will work best for the particular setup. Each pool pump can handle various flow rates and head losses with different horsepowers.

It is important not to choose a pool pump larger than needed. A too-large pump uses extra energy and contributes to higher than necessary energy bills. Using these simple calculations, pool owners can enter a shop prepared to purchase the correct pump for their individual setup.