DE Added to Cartridge Filter


Bronze Supporter
Feb 10, 2017
Longview / Texas
My pool is not installed yet but I have bought and received my Pentair Clean and Clear 200 cartridge filter. I was reading through the instruction manual and noticed this passage:

"When the cartridge element filter is used on new pools and after cleaning the elements, introduce into the system .5 pounds
of diatomaceous earth per every 100 square feet of filter area, (a one-pound coffee can equals .5 pounds of diatomaceous
earth). Mix the diatomite with water and pour it into the skimmer after the pump is primed and the system is operating. This
will enhance the filtration of your water."

Has anyone done this? I have read other posts that did not recommend doing this. Thanks.


TFP Expert
Platinum Supporter
May 23, 2015
Tucson, AZ
I would NOT recommend doing this. DE will become entrained into the filter medium and will not be removed with simple hose washing. You will irrevocably reduce the filtration rate of the filter cartridge. It will certainly make the filter remove finer particulates but at the cost of compromising the element. On a new plaster pool and depending on startup process used, one can get some plaster dust (calcium carbonate particulates) to develop. That will certainly clog up a new cartridge filter quickly. However, plaster dust can be cleaned from a filter if it is heavily lodged into the media - you simply acid soak the filter (but ONLY after first cleaning in it in TSP to remove oils) and the acid will dissolve the plaster dust. DE is made of crystalline silica particles which will not be dissolved by acid.

Do yourself a favor and just ignore that part of the manual.