Look for an inexpensive Polyquat 60. Anybody have any luck with the Pool Solutions P81001DE Algae Prevent 60? Seems to be various prices for the PQ60, just wondering if there is really any difference. Thanks!!
From what I can see that looks the be the right stuff. You want Poly[oxyethylene(dimethyliminio)ethylene(dimethyliminio)ethylene dichloride]. I am convinced I can make that out on the label in the photos I've seen, but it gets blurry.