I am not really sure what it is, but I am a bit freaked out about it now..
I was running my hands on the pool walls, and I can feel graininess. Its like when I run my fingers some small grainy/sandy substance comes out. When I look closely I can see white granules coming out of the wall as I run my fingers.
What is it? Is it calcification? or is it that some substance is corroding the walls and what is coming out is part of concrete?
There is also powdery substance at the bottom of the pool and the pool steps and when I brush they just come out and make the pool cloudier.