fall chemicals needed

I have a ig liner pool 20X40. What chemicals do I need other than bleach and algecide to close down? I place a cover and do not drain down. I usually run my pool only if it looks like a freeze that night. Last year it only got down a few times in Tenn. I just don't want to open up to a bunch of algea. I had to install a new liner this year.
thanks

I raise my pH up to about 7.6-7.8 range just to account for dilution from melting snow and draining. Want to insire it does't drop below 7.
Al