How Much DE for Pool Filter Do You Actually Need?


Are you sick of wasting hours figuring out how much DE you need for your pool? Do you feel unable to begin because of the wealth of knowledge available on the Internet? If so, you're not by yourself. Many pool owners have the same problem and are searching for a solid answer. Thankfully, figuring out how much DE is required doesn't have to be difficult. You can quickly assess how much your pool needs with the correct information and tools. This will not only spare you time and effort, but it will also guarantee that your swimming pool is well-maintained and secure. Continue reading to find out more about how to calculate the ideal DE dosage for your pool and why accuracy is crucial.


Pool de is an essential component of pool maintenance and upkeep.

  • It helps to keep the water clean and clear.
  • It prevents algae growth and other contaminants from forming in the water.
  • It also helps to balance the pH levels of the water, making it safe for swimming.

By understanding how much de for pool you need, you can ensure your pool is always in top condition!

Are you having trouble figuring out your DE filter?

Do you find yourself stuck between adding too little DE to do the job right and putting so much that it washes into your pool?

Do you feel like there’s no real way to know how much DE is right for your filter and your pool?

Whether you’re in the market for a DE filter or you just brought one home, it’s a good idea to familiarize yourself with the right way to operate these excellent products. With this article, you’ll be able to learn all about how to calculate how much DE for pool filter use you need every time you clean your filter.

You’ll also learn a little bit more about what a DE filter really is and why it’s such a popular choice with pool owners everywhere. No matter what you hope to learn about these filters, this crash course article is here to help!

Read on to discover more information and determine if these filters are right for you.

*HOW TO COMPUTE* the Right Amount of DE

Computing the right amount of diatomaceous earth for your pool filter depends entirely on whether this is the first time you’re filling it or this is one of the many times you’ll be backwashing and cleaning it. The two formulas you need to use to compute how much DE to add to pool filter products in both of these instances are listed below, and each one has a couple of sample computations to help you better understand how to determine the answer. Remember that, if you don’t know how many square feet of water your pool filter covers, your instruction manual should tell you. If you can’t find your instruction manual, call your local pool store or search the brand and model of your pool filter to find this information.

*HOW MUCH* DE is Needed for a NEW FILTER?

When starting up a new filter, you need to add a little bit more DE powder than you would for an already established filter. This is just to be sure everything is functioning as it should, and to help “prime” the filter with DE, so to speak. You will need to use one pound of diatomaceous earth powder per 10 square feet of filtered pool water.

To get started with your new DE filter, use the formula below.

Calculation Formula

  • Square feet serviced by your pool filter (s) x 0.1 = total number of pounds of DE needed (DE)
  • S x 0.1 = DE

Sample Calculations

Let’s say your swimming pool filter is a 24 square foot version and you’re starting a new filter. We’ll use the above formula to figure out how much powder you should use.

  • Square feet serviced by your pool filter (24) x 0.1 = total number of pounds of DE needed
  • 24 x 0.1 = 2.4 pounds of DE

What about a big 60 square foot pool filter? Don’t worry, the same formula works the same way.

  • S (60) x 0.1 = DE
  • 60 x 0.1 = 6 pounds of DE

No matter how small or large your pool filter might be, the same calculation can always give you the right amount of DE for your filter purposes.

*HOW MUCH* DE is Needed for a BACKWASHED Filter?

A filter that has already been backwashed can have a little bit less DE added to it. This is for two reasons: because it’s already been established and is functioning properly, and because some DE is always going to be left behind while you’re backwashing. While some companies will suggest slightly different calculations than the one below, this one will give you a good starting point for adding the right amount of DE to your filter. If you find that this is too much or too little after a few uses, try adjusting the final result by just a few tenths of a pound.

To calculate this number, first calculate the amount you’d need for a new filter, and then find 80% of that number.

Calculation Formula

  • Square feet serviced by your pool filter (s) x 0.1 = total number of pounds of DE needed (DE)
  • S x 0.1 = DE
  • Total number of pounds of DE needed (DE) x 0.8 = total number of pounds for backwash (BW)
  • DE x 0.8 = BW

Sample Calculations

Let’s look at our two sample pools again. First off, let’s start with a 24 square foot pool filter that needs to be backwashed.

  • S (24) x 0.1 = DE
  • 24 x 0.1 = 2.4
  • 2.4 x 0.8 = BW (1.92)

You would need 1.92 (or round down to 1.9) pounds of DE for backwashing this filter.

Now let’s try our 60 square foot pool filter.

  • S (60) x 0.1 = DE
  • 60 = 0.1 = 6
  • 6 x 0.8 = BW (4.8)

You’d need 4.8 pounds of DE to backwash this filter.

*HOW TO REPLACE* DE in a DE Filter

Every time you clean your DE filter, you’ll need to replace the DE inside. This needs to happen every month. If you don’t clean and recharge the DE in your filter, you run the risk of a lot of contaminants building up on your filter media and causing the filter and, in some cases, the entire pool to quit functioning properly. Stay on top of this maintenance to keep your pool water safe, clean, and crystal clear.

  • Start by backwashing the filter. Turn the filter valve to “backwash” and turn on the pump. Let it run until the water that comes out of the hose is clear. When the water is clear, your filter has been backwashed.
  • After this step, turn off the filter pump. Open the filter’s air relief valve and remove the drain plug. This will let the water in the tank drain out.
  • Open the filter. This will probably involve removing a spring clamp closure, but it might also involve using tools to unscrew bolts or screws that hold it in place.
  • Remove the inside manifold piece and take out the grids.
  • Use a garden hose to rinse the DE and contaminants from the grids. Use your hose to rinse the inside of the tank, too.
  • Return the grids and manifold to the tank.
  • Prime the pool pump by adding some water into the basket. Replace the lid and close it tightly.
  • Open the air relief valve to remove air from the tank.
  • Turn on the pool pump and close the air relief valve.
  • While your pump is starting up, combine the correct amount of DE with enough water to make the consistency creamy and smooth.
  • Once the pump is running, pour this mixture into the skimmer basket in your filter.
  • Let the pump run for 30 minutes before using the pool.

What is a DE Filter?

You’ve probably heard the term diatomaceous earth, or DE, being thrown around if you’ve done much shopping for pool filters. But if you’re a little bit inexperienced in the different types of filters available, you might be wondering just what this actually means. Before you learn more about the filter, it’s a good idea to understand what diatomaceous earth itself is.

DE is natural sedimentary type of rock that crumbles very easily and can form a powder. It’s very porous and abrasive, which makes it a great option for filtering contaminants out of water. It’s found in a lot of different products, and it’s not just used for pool filters. You can also find it in toothpaste, dynamite, cat litter, and even used in some outdoor gardens.

DE can also be used to filter water in fish tanks and in large-scale drinking water treatment facilities, too. It’s not just for pools and hot tubs—any water has the ability to be filtered and cleaned up through the use of diatomaceous earth. It’s even used for filtering food and beverages like honey, sugar, wine, and beer, because it’s capable of removing unwanted particles without changing the taste or chemical makeup of any of these substances.

How does a DE Filter Work?

Diatomaceous earth filters can filter down to 3 to 5 microns, which is generally quite a lot more filtration than you can find with other types of filters available on the market today. But how do they do it? In this section, you’ll get a quick run-down of how these filters work so you can better understand just what you’ll be using the DE for when you install one.

  • The filters are made up of a manifold system inside a tank.
  • The manifold features several grids which are made of fabric filter media much like a cartridge filter. While some people may believe these are the actual filtration portion of the filter, that isn’t quite true.
  • The diatomaceous earth that is placed inside the filter clings to the fabric in the grid media. This may seem like a bad thing, but it’s actually very beneficial for the fabric media.
  • Ordinarily, fabric media filters can clog up almost right away while a pool filter is in use. With DE stuck to them, however, the water that passes through is filtered much more finely, and the DE ends up catching the contaminants instead of allowing them to pass onto the grids.
  • As such, the powder itself is the filter and the fabric grids only work as a sort of holder for that powder.

You can tell when your DE needs to be changed because the pressure will begin to rise within your filter tank. This means that water isn’t flowing the way it should anymore, and your filter will need attention at this time.

Why are DE Filters Popular?

There are a lot of different reasons why pool owners may choose DE filters over other types of filters. While it’s true that these are some of the more expensive filter options on the market today—although sand filters are often a little more costly, especially in the long run—they still remain very popular choices. Check out the list below to help you understand what brings pool owners back to these filters time and time again.

  • DE filters offer much more filtration. These filters are the number one choice for anyone looking to get rid of the largest number of contaminants as well as the smallest possible particles.
  • DE filters can last a long time. With proper maintenance and regular cleaning, the grids inside the filter can last from anywhere from five to seven years. This is much longer than sand or cartridge filters can last, even with perfect maintenance routines.
  • DE filters are relatively easy to clean. They don’t require any overnight soaking or harsh chemical cleaners, which are both excellent reasons to bring one home for your pool. All you have to do is rinse them and add more DE when the time comes.
  • DE filters come with pressure gauges to help you tell when it’s time to clean. These gauges can give you a good idea of when your filter is getting too dirty and may need to have the grids and/or DE flushed and changed.


By now, you should have plenty of information to help you get started with your diatomaceous earth filter. You should be well on your way to understanding the right amount of DE to add to your filter, whether you’re starting it up for the first time or backwashing it for the tenth time or more. With the right information to help back you up, it should be easier than ever before to understand how to add DE to your filter and why it’s such a popular choice to do this in the first place.

Although DE filters can be a little confusing if you’re used to simple cartridge media filters, they don’t have to be. Keep the right formulas in mind and you’ll be able to clean and recharge your DE filter the right way every time. You’ll be surprised at just how clean and healthy your pool water will be!

Additional Research:

5 Tips to Help You Determine How Much DE for Your Pool

  1. Check the manufacturer's instructions for your pool filter to determine the amount of DE powder you need.
  2. Calculate the surface area of your pool and use this number to determine how much DE powder you need.
  3. Test your pool water regularly to ensure that the pH levels are balanced and that there is no excess chlorine or other contaminants in the water.
  4. Clean out your filter regularly to prevent clogging and ensure that it is working properly.
  5. Replace your DE powder every 3-4 months, or as needed, to keep your pool clean and safe.

ALSO: Consider using a DE filter system for an even more efficient filtration process!</p

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About The Author

Joseph Bartley
Twitter | Crunchbase

Joseph Bartley, also known as the WaterFilterFanatic, is a seasoned content writer who specializes in water filtration and water quality topics. On AllAboutWaterFilters, he has written a range of water filtration system reviews, water health and quality articles, swimming pool, hot tub and aquarium filtration guides, DIY methods to assist people clean their drinking water, and much more. Joseph enjoys spending his time working with the #AllAboutWaterFilters Editorial Team to provide some of the best quality water filtration content available on the web.

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