Adding DE to a Pool Filter

A small pile of DE (diatomaceous earth) powder.
  • 1-3 hours
  • Beginner
  • 0-500
What You'll Need
What You'll Need

A DE pool filter is used for cleaning the water in a swimming pool by removing accumulated debris. A DE filter is different from conventional sand and cartridge-based filters. It uses a special ingredient called DE powder, which stands for "diatomaceous earth." DE is commonly sold at pool supply stores in the form of a coarse white powder. It is actually a form of ground up algae fossils that is retrieved from the bottom of deep lakes, and is also used in gardening, construction, and numerous other applications.

While adding DE to your pool filter is a simple task, you must take proper precautions to prevent damage to your filter. Overloading the filter with powder can backfire and cause the grime to get deposited at a much faster rate. Excess DE will then have to be removed with a special type of vacuum.

Step 1 - Backwash the Filter

Before adding the DE powder, you should use a hose to thoroughly backwash the swimming pool’s filter. Backwashing is a process of flushing out the debris from the filter tank by reversing the flow of water; here, water is sprayed down the standpipe and over the sand. Dip the filter in the bucket to rinse it off and finish the backwashing.

Step 2 - Measure the DE

A label on the side of your filter should list information regarding how much DE powder to add.

As a rule of thumb, add half a cup less than what the label says. Reduce the total amount to compensate for residue that is left inside the filter, no matter how thoroughly you rinsed it. This also avoids overfilling the filter with the powder.

Step 3 - Add the DE to the Filter

Use an empty coffee can to scoop out the DE from its packaging. It is best to add the DE through the pool skimmer. Use the skimmer to avoid spilling the powder.

When dispensing the powder, ensure you work slowly. You should not add more than one pound of DE powder at a time. Let it settle for a minute or two, and then repeat.

Step 4 - Avoid Overloading

Dump the DE in the skimmer, and wait for the water to clear up before adding the next scoop. If you find the water isn't clearing up fast enough, the skimmer might be clogged with too much powder.

When the required amount of DE has been added, fasten the lid of the skimmer.

Step 5 - Check your Filter System

No DE powder should be oozing through the pool’s return fittings. Ensure the multi-port valves are tightened because in old pools, the DE often leaks through them.

Any DE powder appearing in the pool means that either the filter is clogged or it is malfunctioning. Excess clogging can be resolved by removing some of the powder.