How Do You Clean a Hayward DE Filter?

To clean a Hayward diatomaceous earth filter for pool maintenance, use the backwash setting on the filter to remove the existing DE; then reapply new DE. A DE filter uses diatomaceous earth, a crumbled soft rock, to filter impurities from the pool. Backwash the filter when the filter pressure rises 8 to 10 PSI over the clean starting pressure.

  1. Empty the pool skimmer basket

    Empty the pool skimmer basket to prevent leaves from being sucked into the filter during the backwash process.

  2. Turn off the pump

    Empty the strainer basket from the pool pump, and then turn off the pump.

  3. Set the valve to the backwash setting

    Rotate the knob or slide the lever up to select the backwash setting on the filter valve.

  4. Turn on the filter

    Turn the filter on, and let it run for 20 to 30 seconds, or until the water runs clear.

  5. Turn off and reset the filter

    Turn the filter off, and then set the valve back to filter. Turn the filter back on. Do not set the device to filter with the filter turned on. Doing so may cause damage to the filter or injury to yourself.

  6. Add new DE to the filter

    The backwash process removes 80 to 90 percent of the DE. Add the entire recommended amount of DE back to the filter. A general guideline is to add 1 pound for every 12 square feet of filter area. If DE washes into the pool from the filter, vacuum it out after it settles, and next time add 1 pound less.