algaecide made water cloudy and created foam


Active member
May 10, 2014
Falls Church, VA
I am closing my pool today. After lowering the water a few inches below the skimmers, I added a quart of HTH Super Algae Guard 60 (polyquat 60) and let it circulate a few hours. The water is now cloudy enough that I can't see the remaining leaves on the bottom (I'm fairly sure there are a few left down there), and there is foam on the surface. Did I add too much? Should I do anything about it, or just go ahead and close it? I would like to finish closing the pool today.

Also, I read somewhere (here?) that with a mesh cover, it's a good idea to put floaters with chlorine sticks under the cover at closing. Should I do that, or will that raise the chlorine level enough to destroy the algaecide?

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Not sure about the dosage amount or reaction you're seeing, but at this point there's not much to do but let it run its course. I suspect it will eventually settle and dissipate. If you have already SLAM'd or are assured you are algae-free at a normal chlorine level (hence you added the Poly 60), then I'd just close. I'm assuming your water temp is at or below 60, and the Poly along with clean water, should get you through the next few months. See you next season! :swim:


TFP Expert
Mar 2, 2011
HTH Super Algae Guard 60 is not poly 60.

The manufacturer has presented the product in a deceptive way to appear to be poly 60, but it's really the cheap foamy algaecide.

Poly 60 is Poly[oxyethylene(dimethyliminio)ethylene(dimethyliminio)ethylene dichloride]

The other algaecide starts with something like n-alkyl.