Diatomaceous Earth in Pool

Most think DE (Diatomaceous Earth) will keep water cloudy.  However, DE is heavier than water and will sink to the bottom. Any breach of the filter—torn elements, cracked manifolds or tube sheets, stretched or missing o-rings—can cause earth and other debris to return to the pool.

Do you see a small burst of DE come out of a return when you first turn the pool on?

• It is normal for a small amount of earth to “kick back” into pool with the initial force of water through the filter.  This should be brief. If there is a steady stream of earth blowing into the pool for more than 3-5 seconds inspect the filter nest for cracks or tears.

Do you find earth lying on pool bottom or see it streaming out a of return?

• This is a good sign a part of the filter is broken or needs adjusting and should not be ignored.  Your filter nest must have the appropriate amount of earth coating it at all times and running it short of earth for a long period of time can cause damage to the element.
• The elements are a great place to start inspecting.  Whether your filter is a grid or finger filter the nylon should always be intact and never torn, ripped or worn thin.  Weak spots in the nylon will open under the running pressure of the equipment and earth (and everything else you’re trying to filter) will have a way to pass through the filter and get into the pool.
• For Grid Filters
  • Check the grid collector (large plastic piece organizing all the grids) for any cracks.  Even a small hair-line crack could open up under the running pressure of the equipment. 
  • There is a small “finger” on top of the grid collector, be sure it is intact
  • The o-ring on the pipe attached to the filter tank (this is the pipe the grid collector slides onto) should not be stretched or crimped.  
• For Perflex (Finger) Filters
  • The plastic sheets that the fingers sit in (there are two—a  top & bottom sheet) should not have any cracks.  Again, even a small hairline crack could open up under the running pressure of the equipment.  If you notice a crack in one of these “tube sheets” inspect the other carefully, usually if one goes the other is not far behind.
  • The two tube sheets are held together by several nuts & bolts.  Be sure all nuts & bolts are tightly screwed together.  None can be missing or loose!  A missing set would allow DE to pass through the filter back to the pool. 
  • There is a large diaphragm gasket in between the two tube sheets that should not be crimped, puckered or stretched out.
  • The bump shaft is a metal rod that runs up through the tube sheets and connects to the bump handle. If the bump shaft is corroded or missing o-rings or washers this can also leave enough room for earth to bypass the filter.

If you can’t find the source of the problem or would prefer to have one of our techs look at it, feel free to drop your filter off in-store or schedule a service call!