So my pool is a salt water pool. We use the Simple Salt System. The water is very clear but I always get little piles of, what I'm guessing is algae but I don't know, on the bottom. Tried shocking, tried algaecide, i've vacuumed to waste more times than I can count, Ive cleaned my filter cartridge as many times as I've vaccuumed and it still returns. The water is balanced perfectly, pH, Alkalinity, etc. etc. I don't have a clue what else to do. Please help?? Thanks!