Filter Troubleshoot Guide



Frequent Need for Filter Cleaning/Backwashing

  • Make sure your water chemistry is on target.
  • If pH, Alkalinity, or Hardness levels are high, scale may develop in the plumbing, restricting flow, causing filtration issues.
  • Determine the time since your last sand change, DE filter clean, or cartridge replacement. It might be time.
  • Is your chlorine level low, or do you have algae present in your pool?
  • Did you just add stabilizer? This will cause an increase in your filter pressure.
  • Did you just add a chemical that has an increase in filter pressure as a byproduct?
  • Are you backwashing and rinsing long enough when you are performing filter maintenance? Only clean your filter when your pressure gauge shows a pressure increase of 5-7psi above your standard operating pressure.

Sand filter:

  • Has the correct sand been used? “Playground” sand will not work.  You need to purchase the proper silica sand from your local pool professionals, and install it in the proper amounts.
  • Is the sand too old?  It might have debris impeding the flow of water, or channeling and need a sand or filter media change.

DE filter:

  • Are you using the correct amount of DE powder?
  • Too much DE powder will not sit properly on the DE grids, which will reduce the effectiveness of the DE powder, causing a shorter filter run between cleanings.
  • Has your DE filter had a thorough filter cleaning? It might be time to really service your filter.
  • Are your DE grids in good condition, or old, worn or torn. These can only be checked during a DE filter clean, so consider doing that next.

Cartridge filter:

  • When is the last time your filter elements have been cleaned?
  • Is it time to replace them?
  • Have you added a product to your pool to floc or coagulate metals? This is a common cause of impeding the function of a cartridge filter.
  • Are your cartridge filter pleats torn or frayed? Time to replace.
  • Are your cartridge filter bases or any parts torn or damaged? Time to replace.

Sand Is On The Floor Of The Pool (For those of you with a sand filter only)

  • A lateral, which is at the bottom of your sand filter, has either cracked or is broken, allowing sand to pass through the filter, enter the return (plumbing) lines, and enter the pool, via the return jets. Either way, all the sand has to be removed.  Then, each lateral must be removed and inspected in order to determine which lateral(s) are cracked or broken.  Once found and replaced, the sand has to be put back into the filter.  If it has been a few years since your last sand changeit is time to do a sand change as well. Sand changes should be done every 3-5 years or as problems present with your filter.
  • When sand was last added, was it the correct amount? Overfilled filters can force sand through into the pool.
  • Is your pump running at the correct speed or strength? Especially with new variable speed pumps it is possible to overstress a filter, especially if it is not sized for additional water flow. Run the pump at a slower speed to see if it prevents the issue.
  • You may not be backwashing or rinsing long enough.
  • If your sand is fine like silt, it may be debris coming back through your filter system.
  • When replacing the sand, be careful. The weight of the sand could crack or break your laterals, and cause the issue without you knowing the damage occurred.
  • If you do add sand to the filter yourself, add water to the filter to just cover the laterals, and then slowly add sand, being careful not to get any into the center filter tube.

DE Powder Is On The Floor Of The Pool (For those of you with a DE filter only).

  • Are your DE Grids torn or frayed?
  • Have you added too much DE to your filter?
  • Is your manifold within the DE tank damaged?
  • Did you spill last time you added DE to the pool?

If any of the above are the case, DE filter service is in order.