Hello. Last year I hired a pool company to prime a tricky waterslide pump system, and they took the liberty of adding chemicals to my pool. Ever since that time (at least from what I can remember), I have noticed white colored blotches on the pool floor. The floor is coated with small pebbles, and you can see large white blotchy areas all over the pool floor (really bad in the deep end, but the whole pool has white areas). If you look a the pictures, you can see where the in-floor cleaning system has created star shapes from the flow pattern. In the star patterns, there are dark areas (original blue floor color) and the white/blotchy ares. How can I identify the white stuff? I'm guessing these areas are either coated with a calcium-type deposit...or could the white areas be bleached? I'm guessing it is the former, but any help is appreciated. I've tried to scrub some of the white areas with a steel brush, and while it seems impossible to remove, I believe hard brushing will remove slight traces of the white stuff. Thanks!