I added stabilizer according to what the pool store tested and said I needed, 2 lbs. I am having a recurring problem I thought I had cured. I keep getting large areas of grey/or brown stains on the pool floor that do not brush off. Not spots. They clear up when I shock, and after a day I vacuum to waste the residue from the pool bottom. So, algae I assume.

Battled this all last summer. When you told me about the metal free working against the copper in the Frog system, I figured that's what
the problem was. But I have discontinued the metal free and just had it happen again.

The water looks great and tests fine, and I have been testing for phosphates also. Thanks for your help.