My 10,300-gallon pool has a nice blue "field tile" below the waterline but has a darker blue tile for the top 6." So the waterline is 4" from the top. I get some (not a lot) of white residue on the tiles above the waterline and I believe it is from the calcium in the water. I have been looking at an Orenda product, SC-1000, that is supposed to reduce this scale and I am wondering if anyone at TFP has any opinions/experience about this. I am very reluctant to put anything unnecessary in the water but the whiteish stuff on the top tiles is not cool, IMO.