I am new to this wonderful site this year. I know it's early, and I just got my water "Pool dealer" free from all their chemicals by using the BBB method. At the end of next month or the beginning of October, I will have to close the pool. I live in Ohio and winters are totally unpredictable. I have read Pool School and it looks like all I will need is Liquid Chlorine and PolyQuat. Is that correct? I have never heard of PolyQuat. Is any other type of algaecide ok?