Hello and Help,
I put 2 orange orb/clor no more, (orange is for 20,000 gals) in my pool 7/8/16 and noticed a small staining spot at bottom of wall where it start sloping down to the deep end within a day or two. I think it's from copper. When first used PH 7.8 Alk 90 Chlor .5 - I removed the...