DE Filter Care
Some existing Credible pools use a DE (Diatomaceous Earth) filter. New pools use the AquaStar cartridge filter — if that's you, head back to the main guide. Below is everything you need to backwash and deep-clean a DE filter.
1
Backwash procedure
Valve positions — turn in one direction to cycle through
Watch the sight glass — stop when water clears
Quick clean (short backwash)
1 · Backwash
→
2 · Rinse
→
3 · Filter
Stop when water turns white (~1 min). Do NOT add DE powder.
1
Turn off pump — open backwash valve (if applicable)
Spin valve in the same direction to the Backwash position.2
Turn on pump — stop when water turns white
Watch the sight glass or backwash hose. Takes less than 1 minute. Do not add more DE powder after a short backwash.3
Turn off pump — spin to Rinse
Turn pump on and rinse for ~20 seconds.4
Spin to Filter — turn pump on
Pressure should drop and flow should increase. Check the returns for good movement. Your heater and chlorinator should now be working — always verify.Full clean (full backwash)
1 · Backwash
→
2 · Rinse
→
3 · Filter
Stop when clear (~5 min). Add DE powder after.
Same steps as above but run until the water runs clear (~5 minutes). Once back in Filter mode, add DE powder through the skimmer — use approximately half the amount listed on the filter sticker. Too much DE can clog and damage the grid.
Important: A full backwash does NOT remove all DE. A complete disassemble is needed to fully clean (see Section 7).
Recirculate tip: The Recirculate valve position bypasses the filter — great for adding chemicals through the skimmer to distribute evenly. Always return to Filter mode and run for a couple of hours to fully circulate.
2
DE filter deep clean
DE filter (Hayward / Pentair vertical grid)
Vertical grid DE filter — lift straight up with a slight twist to remove
1
Start with a thorough backwash to remove as much DE as possible.
2
Loosen the bolt and remove the clamp with the proper wrench or socket.
3
Lift straight up on the sides of the top manifold with a slight twisting motion. Two people may be needed.
4
Do NOT take the grid assembly apart. Spray grids gently with a hose, getting fully in between on both sides.
5
Degrease with a filter degreaser — we recommend Zep Fast 505.
6
For calcium scale: soak grids in a 20% muriatic acid solution (5:1 water to acid) in a large clean trash can for several hours, then rinse thoroughly.
7
Inspect all grids for tears, rips, or cracks in the manifold. Replace damaged grids.
8
Replace grids, lubricate the O-ring with silicone spray, and reassemble. Recoat with the recommended DE amount from the filter sticker.
DE powder appearing in your pool water means the filter grids likely need replacing. Also replace if pressure stays high even after a full clean.