With its ability to remove dirt particles as small as 2 microns in size, a diatomaceous earth (DE) pool filter has the ability to maintain crystal clear pool water. Because the filter filters out such small dirt particles, it's important to keep it clean. If you notice the pool filter gauge rising and the water return flow diminishing, it's time to clean your diatomaceous earth filter. Fortunately, because of the backwash capability on DE filters, cleaning it is easy.
Flip the control valve to the "Backwash" position. Most diatomaceous earth pool filters have a control valves which allow you to switch the filtration from filter to backwash. To clean the DE filter, you must set the valve to backwash mode.
Open the run off valve. The run off valve is where the dirty diatomaceous earth is released from the filter. If you don't want the dirty diatomaceous earth to sit right next to the pool filter, attach a long pool hose to direct the water runoff to a different location.
Turn on the pool filter to allow the dirty water and diatomaceous earth to runoff. Depending on the filter size and the amount of dirt, it can take anywhere from two to three minutes for all of the diatomaceous earth to fully run out of the filter housing.
Shut off the filter when the runoff is clear. Some filters, such as the Hayward Pro –Grid require you to run the filter on a rinse cycle for 20 seconds after a backwash. Not all diatomaceous earth filters have such a requirement. Check with your manufacturer's instruction manual regarding a rinse cycle requirement.
Close the run off valve, switch the control from "Backwash" to "Filter" and turn on the pool filter. After switching the valve back to filtration mode, the water should now flow freely through the filtration system and back into the pool.
Add more diatomaceous earth through the pool skimmer. The amount of diatomaceous earth to add differs depending on the type of DE pool filter. It can be as little as few as two pounds to a many as nine pounds. Check with your pool filter manufacturer's instruction manual to determine how much diatomaceous earth to add back to the filter.