DE Filters

• Hayward's line of DE filters is called Perflex. These filters come in a wide variety of sizes and are filled with a powdery substance that assists in water purification.
  
  If a filter leaks from the bump shaft, then the O-rings on the bump shaft are worn or broken and must be replaced.
  
  A backwash valve that leaks after you shut it off needs to be replaced. Until replacement, a plug with an O-ring can be screwed into the end of the backwash line.
  
  If you press the bump handle up and down and it still feels loose, then one of the C-rings connected to the bump shaft is broken or damaged. Both need replacement.
  
  If the filter lets diatomaceous earth powder back into the pool, then the filter grids, filter fingers, filter manifold or multiport section of your filter may have a crack or rip. If no damage is found, check the tube sheets through which the filter fingers slide. Cracked ones should be replaced.
  
  When a filter's multiport is on but filtering does not seem to happen, the spider gasket inside the multiport may be damaged or worn and in need of replacement.
  
  If the filter gauge shows high pressure but the filter does not run, then it most likely needs a new gauge.
  
  To find what causes a backwash line to have water coming from it when the multiport is set to filter, check the multiport gasket for wear or damage. The multiport gasket, or the entire multiport, may have to be changed.
  
  

Sand Filters

• If your Hayward sand filter continues to run at high pressure even after backwashing, several potential problems could be to blame. Ensure that the user's manual instructions for the filter are followed. Impurities in sand may cause it to clog the system, which means it needs to be changed. Before doing that, though, remove about 1 inch of the top layer of sand and replace it with new sand. Cleaning the filter system with a specialized filter system cleaner can help, too. An improperly closed or partially closed valve can cause problems, as can a pump and filter that don't work well together. If the pump doesn't deliver at least 60 percent of the filter's flow rate, it will never work properly.
  
  To troubleshoot a filter that is short-cycling, meaning that it builds up pressure very quickly after backwashing, check the user's manual to see if the backwashing period is long enough. Live algae clogging a filter leads to problems, too. Likewise, the sand bed may have mineral deposits and need replacement. Pool water can be tested at your Hayward dealer.
  
  If you see sand at the bottom of your pool, it could mean the sand is too small. No. 20 silica sand, .45 to .55mm size, is required in a Hayward filter. Too much sand may be in the filter and causing a problem.
  
  Dirt found inside a filter indicates broken laterals. The multiport may need servicing, and air could be passing through the filter.
  
  

Cartridge Filters

• When a cartridge filter does not clear algae from a pool, some element of the filter is dirty. Specialized chemicals may need to be added; a Hayward dealer can provide information.
  
  If you can see dirt on the bottom of the filter element, then too much water flows through. The size of the pump needs to be reduced.