Thanks, Chemgeek! I was reading some more posts where some people said they used the algaecide when they close, and others say that they don't use it and just shock their pool like crazy when they open in the spring.
I like to add as little chemicals to my pool as possible, but if I'm going to get algae, I think I'd rather add the algaecide at closing instead of fighting algae in the spring.
As far as dosing, would it be a maintenance dose, or a dose for someone who has algae already?