You may have heard that DE powder is the magic ingredient for keeping your pool crystal clear. But what exactly is it, how often should you replace it, and how much DE powder should you use for your pool filter?
DE stands for diatomaceous earth, a naturally occurring sedimentary rock or sand extracted from the ground and crushed into a powder. When added to your pool filter, DE powder functions as a sponge, allowing water through but straining out even the tiniest particles of dirt and debris.
It’s essential to replace DE powder in your pool filter regularly to keep your swimming pool from getting cloudy. You also need to be sure you add in the right amount of DE powder. Too much, and your filter can run too slowly or break down. Too little, and you’ll get a buildup of dirt which can also ruin your filter.
Let’s explore how much DE to add to your pool filter for regular upkeep and complete cleaning. We’ll also explain how to measure it and give you a handy rule of thumb.
For New Filters or Full Cleaning
The amount of DE powder needed will be the same for a complete cleaning or a completely new filter since both start with a “clean slate.”
The way DE powder works is by thoroughly coating your filter grids. As water passes through those grids, the DE powder sifts out the most microscopic sediment. Eventually, of course, you’ll have to replace the powder with a complete clean of your filters.
You should do a total DE filter cleaning one or two times per year, as long as you are backwashing your filter every one to three months. A complete clean means taking the filter grids out and thoroughly cleaning them before replacing them.
Most DE filters include a recommendation for the total amount of DE powder on a fresh filter. However, if you can’t find a suggestion from the manufacturer, you can use a simple rule of thumb: For a full clean or new filter, add one pound of DE powder for every 10 square feet of the filter. So, a 48-square-foot filter will need about five pounds of DE powder.
Popular Pool Filter Sizes and Measurements
Let’s look at a few popular DE filters and the recommended amount of DE powder for each.
- Hayward W3DE4820 Pro-Grid – 48 sq. ft. = 6 pounds of DE
- Hayward W3DE6020 – 60 sq. ft. = 7.5 pounds of DE
- Pentair EC-180007 – 36 sq. ft. = 3.6 pounds of DE
- Waterway Crystal Water – 60 sq. ft. = 6 pounds of DE
Note that Hayward recommends a slightly higher amount of DE than our “rule of thumb.” You can test out the amounts yourself and decide what works best for your pool. For more specific filter recommendations, head over to my guide on the best pool filter.
For Backwashing Your Filter
To keep your pool in tip-top shape, you should backwash your filter every one to three months. Backwashing isn’t a complete clean but simply removes the buildup of residue on your filter grids. A lot of the old DE powder will come off, so you need to replace it with fresh powder.
Backwashing doesn’t remove all the DE powder on your filters, so you don’t have to add as much as you would for a new or thoroughly cleaned filter. You only need to add about 80% of the amount you would for a new filter. So, a 48-square-foot filter would need a little less than four pounds of DE powder.
Popular Pool Filter Sizes and Measurements
After a backwash, to get the amount of DE powder, simply take the recommended amount of DE powder for a new filter and multiply it by 0.8, or 80%.
Here are the amounts for popular pool filters:
- Hayward W3DE4820 Pro-Grid – 48 sq. ft. = 4.8 pounds of DE
- Hayward W3DE6020 – 60 sq. ft. = 6 pounds of DE
- Pentair EC-180007 – 36 sq. ft. = 2.88 pounds of DE
- Waterway Crystal Water – 60 sq. ft. = 4.8 pounds of DE
Robelle makes a good replacement DE powder you can use when you're backwashing and cleaning your DE filter.
How to Measure DE Powder
The best way to measure DE powder is with a standard DE scoop. You can buy these at any pool supply store or online. DE scoops make it easy to measure out your powder. Each scoop is equivalent to ½ pound of powder. So, for six pounds of DE powder, you would use 12 scoops.
If you don’t have a DE scoop, though, you can easily measure out DE powder using standard items from your kitchen. The most straightforward substitute for a DE scoop is a one-pound coffee can. One can is equal to ½ pound of DE powder, just like a DE scoop.
However, one-pound coffee cans are challenging to find these days. You can find them in eight ounces, 10 ounces, 24 ounces, but rarely 16 ounces.
Another option is to use measuring cups. The rule of thumb here is: One pound of DE powder equals about 6 cups. You’ll measure faster if you have a two, four, or six-cup measuring cup, but you can use a one-cup measure just as easily.
Number of Cups for a Full Clean
Here’s a quick cheat sheet of popular filters with the total amount of cups needed for a new filter or a complete clean. We rounded each to the nearest whole number.
- Hayward W3DE4820 Pro-Grid – 48 sq. ft. = 36 cups of DE
- Hayward W3DE6020 – 60 sq. ft. = 45 cups of DE
- Pentair EC-180007 – 36 sq. ft. = 22 cups of DE
- Waterway Crystal Water – 60 sq. ft. = 36 cups of DE
Again, note that Hayward’s recommendation is higher than our rule of thumb estimate, so you can play with the amounts to find your ideal setting.
Number of Scoops After Backwashing
After backwashing, you should use the following number of cups, rounded to the nearest whole number:
- Hayward W3DE4820 Pro-Grid – 48 sq. ft. = 29 cups of DE
- Hayward W3DE6020 – 60 sq. ft. = 36 cups of DE
- Pentair EC-180007 – 36 sq. ft. = 17 cups of DE
- Waterway Crystal Water – 60 sq. ft. = 29 cups of DE
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With the guidance above, you should be able to safely add DE powder to your pool to keep it crystal clear and ready for some fun in the sun.
Questions? Let me know, always happy to help.