I think I dumped a bunch of DE in my pool. Now what?


May 1, 2019
Austin, TX
my water is very murky, kinda greenish, and has a fishy smell. It feels a little slimy, though that could be in my head. I noticed my polaris cleaner wasn't being very effective - when I pulled it out, the filter bag was still holding water! I think it may have been coated with DE from inside the bag.

About a week ago, I did a backwash for my DE filter. Unfortunately, when I added the new DE, I had forgotten to turn off the polaris 360 line - which bypasses the filter and pushes water back to the pool. I noticed because I went to check to filter pressure and it was really, really low (which is what happens when the valve to the polaris is open). So I closed the valve and loaded new DE. I checked the pool and didn't see signs of DE, so I thought maybe I got away with it -maybe I didn't understand how the water flows. I hand vacuumed (not using polaris) the next day in hopes of getting any DE that may have gotten in.

But a week later, I now have the symptoms described above. Also my filter was running at TWICE its pressure (from 10 to 20) (I usually backwash at 12). I opened the filter and cleaned all of panels completely. There was a lot of DE in there.
I just scooped some leaves out, and the net had some filmy white stuff, which I'm going to assume is DE.

I had originally thought it was algae, and was just about to SLAM (Does low temperature impact SLAM?). Now my new theory is pointing pretty strongly at DE, so I'm holding off on the SLAM.

Any advice on how to get rid of what is likely a lot of DE in the pool?

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Josh, if that is DE, then you will have to let it settle and slowly vacuum it either to waste or back into the filter at which point you may have to backwash. You may have to do that more than once to remove extra DE. However, if what you are seeing is not DE and actually algae, you will need to do the SLAM Process. The sooner the better. The cold water will not hinder the SLAM, in fact it may help you since algae doesn't grow at such low temps.
  • Like
Reactions: joshf


Mod Squad
LifeTime Supporter
Jan 17, 2012
Evans, Georgia
Good to hear! As to the little DE accident....well....we've all done something crazy and the positive side of it is you will *never* make that same mistake again! And, you learn a little more about your pool in the interim. So its all good!

Maddie :flower: