DE Filter grids permanently damaged?


Sep 24, 2014
San Antonio, TX

I know there's an entire section on cleaning DE filters, which is fantastic information. My grids (2 of them) had a massive area of pink algae on them from an incident that happened right at the beginning of the pool season. We went out of town and accidentally left the filter running continuously. When we can back, the skimmer was completely packed with leaves and the pump was pretty much just sucking air. Rather than cleaning things up and doing a backwash/replenish of the DE right then and there, I thought I'd go ahead and wait until it looked like it was having issues. Well, here we are in August, and what do you know? Issues! It seems like a clump of DE must have come loose and plugged up the filter, as the psi went way down overnight and the pool has the fine white powder on the bottom. I did the backwash and popped the filter open. Oh boy... apparently since the leaf incident, there had been a huge clump of DE packed in between two of the grids. That's where the huge pink algae nest was. I soaked in bleach a couple of times, but can't seem to get rid of the residue on the inside of the grids. I've attached a photo. My question is, are those grids now hosed, since the stuff is on the inside, or should I just reassemble the filter and do the SLAM thing? I assume the algae is actually dead since I bleached the heck out of 'em, but that residue is still there.
grid goo.jpg
Thanks, y'all!


Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Hi Mike. As long as the grid isn't torn, I don't see a problem. The discoloration (stain) may go away, or it may remain, but it shouldn't effect the grid's performance. As long as you didn't run acid over the material which would've infused the grid panels closed, they should perform well. Other than perhaps a very minor amount at initial recharge, I would monitor to ensure no DE is flowing through the grids back to the pool. Also watch the pressure to see if it's remaining constant. Normally a blockage results in an increased pressure, so hopefully no leaves are inhibiting suction flow to the pump. Last, to ensure you have the algae issue well behind you,watch your FC consumption each day. If in doubt, do an Overnight Chlorine Loss Test.

Final step ....... get in there. It's hot. :swim:
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