Couple questions..this is the first year I haven't used the frog mineral back....I have some spot stains developed over the years - rust/orange spots the size of a silver dollar or smaller - scattered around. also about 3 x 3 ft of stain around the drain in the deep end. that I thought was organic but hasn't faded from chlorine over the years.
today started using ascorbic acid in a sock - removes the stains in the shallow end in about 2 minutes - leaves a mottled look (not very noticeable)
1- do you think spot treating the stains this way without using a sequestering agent will prevent return of stains?
2- is it normal that the AA causes a black or grey stain sometimes - that seems to fade in an hour or 2?
3- do you think the stains are from the metals used in the Frog mineral pack?
4- would spot treatment of AA in a sock be able to treat a 3x3 area at the deep end drain?
I am a little concerned about a full treatment of the pool that requires low chlorine levels during the heat of the summer.