I typically use a 60% Concentrated poly-quat from Kemtek for two occasions: (1) during spring startup and (2) after heavy rains add several inches of water during the season. Otherwise, the TFPool method and test kit keep my water clear and safe.
I use the 60% algaecide after rains just to "help" the chemicals keep green stuff from starting. I usually add 8 oz. total for the 35K gallons.
I erred in my last order of algaecide thru the mail and didn't read the ingredient info on the webpage. I thought InTheSwim super algaecide on sale was the same 60% poly-quat I had ordered from Kemtek. However, the InThe Swim super algaecide contains 23.5% copper triethannolamine complex as the only active ingredient.
My question is: can I safely use this copper-based algaecide instead of the poly-quat type for my maintenance after rains?
Or, should I just keep it on-hand for major problems and stick with the poly-quat?
My greatest concern is water safety for my two grandkids (ages 6 and 2) and their friends.
My vinyl liner is way over 12 yrs old and has been bleached white (except for several winter stains) and I'm not concerned about copper staining.