I've been using Phosphate remover every other week (~1 oz) to keep it below 100. This is the first year that my pool has zero algae. I have a salt water pool.
FC:2.5
CC:0
pH:8
TA:120
CH: 280
CYA: 80
Salt: 3200
Phosphate: <100

I don't use Phos-Free that was recommended by Leslie's because it adds CH. I bought one made by HASA, and its called Phos Out. Stuff works great.