Normal for DE to be in pump strainer atfter shutdown?


Well-known member
May 26, 2007
Hi All,
My pump is on a timer and at shutdown DE backs up into the pump strainer. I know this because the water inside the pump housing is milky white. Is this normal?



Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
Sebring, Florida

This is a complete guess but it makes sense that if you see DE, the water in your system is "backing up" when you turn off the pump.

The only way I can see that occuring is if you have an air leak (probably tiny since it doesn't lose prime) somewhere in the system.


Well-known member
May 26, 2007
Thanks for the responses. Upon further reflection, I think I know what is happening.

The original PB did not use any check valves in the system. I have a spa that is higher than my pool. When I shut the pump off the water tries to equalize and pushes backwards from my spa return through my pool returns and main drain/skimmer resulting in the DE in my pump. Sound possible? I bought a check valve prior to noticing this problem, just haven't installed it yet.

In the morning the pump basket is still full of water so I don't think I have a leak. Also when I installed the filter I literally weighed out the DE. I have heard of adding 80% of the suggested amount though.

Sound reasonable?