Quote Originally Posted by SoCalBoo
Posted below, but no one responded. If anyone can just respond briefly, I'd appreciate it.

Have 22,5k gallon IG, plaster, SWG. Have mustard bloom. Raised ch to 15 for a few days, it left briefly but came back. About the only other thing I can think of doing, besides elevating the chlorine back up for additional days, is to add poly.

The back of the bottle (60%) says 11 to 17 oz per 10k gallons. that would be about 28 oz to the whole quart full. But I was at another store today and saw that another brand of same stuff, same concentration, said 8 oz per 10k of pool? How much should I add?

Also, ch levels still elevated. Should I go ahead and add now, or wait for ch to come back to some level?

thanks
Boo, I recommend you read this article by Ben on algecides before proceeding with polyquat: http://www.poolsolutions.com/tips/tip08.html. If your CYA is really 60 ppm, chlorine is probably your best bet for knocking out the algae. If it's higher, you may have to use the polyquat or some other algaecide. Before using one of the bromine or ammonia based products however, you should read this article: http://www.poolsolutions.com/tips/tip10.html.

To answer your original question, if you do go with the polyquat, I'd dose at the rate that the manufacturer of the particular product you buy recommends.