I have a 12x3ft above ground pool. After being gone for a weekend and levels dropping, I have had nothing but problems with algae. Got rid of it I though, and it came back with a vengence. Decided to drain the whole thing and refill rather than buying expensive products I don't know how to use. How would you suggest I clean the pool (any special cleaner or mixture?) to make sure I get rid of ALL the algae so it doesn't come back? After cleaning, would you suggest I let it dry out for a certain amount of time before refilling to make sure everything is dead? I'm still new to this, so thanks for helping me!