Run your pool filter continuously and brush fine dirt toward the main drain — this suspends the settled particles so your filter system can pull them out and trap them in the filter media.

Fine dirt and dust settle quickly to the pool floor because the particles are heavy enough to drop out of circulation when pump flow is low. Brushing the floor and walls stirs that sediment back into suspension, where your pump's suction draws it through the filter. A flocculant can accelerate this by clumping fine particles together into larger masses that your filter catches faster — particularly useful after a dust storm or heavy rain event that dumps fine debris into the pool.

  • Continuous filter runtime of 8–12 hours after brushing gives the filter adequate time to clear suspended fine dirt.
  • Pool flocculant (alum-based) clumps particles as small as 5 microns — well below what a standard sand filter captures alone.
  • Cartridge and DE filters trap finer particles than sand filters: DE captures down to 2–5 microns, cartridge down to 10–15 microns.
  • Backwashing a sand filter after a heavy dirt event removes trapped sediment and restores flow rate within 2–3 minutes.

Step-by-Step

  1. Turn the pump to continuous run: Set your pool pump to run for the full clearing cycle — plan on 8–12 hours minimum before expecting visibly cleaner water.
  2. Add flocculant if the dirt load is heavy: Pour an alum-based pool flocculant into the water according to the label dosage — this clumps fine particles down to 5 microns into larger masses your filter can catch.
  3. Brush the pool floor and walls toward the main drain: Use a pool brush on a telescoping pole to push settled fine dirt off the floor and walls, working in slow, overlapping strokes so you suspend the sediment rather than scatter it.
  4. Allow the filter to run undisturbed for several hours: Resist brushing again mid-cycle — let the pump draw suspended particles through the filter media before you add more sediment back into circulation.
  5. Check filter pressure and backwash or clean if elevated: After a heavy fine-dirt event, sand filter pressure often rises 5–8 PSI above baseline; backwash for 2–3 minutes or rinse a cartridge element to restore flow rate.
  6. Re-brush any remaining patches and run the pump an additional 2–4 hours: Stubborn fine silt on the floor floor after the first cycle usually clears with one more brushing pass followed by a shorter additional filter run.