white chalky like substance at bottom of pool

[ruthie]

I hope you can help. I have this white residue laying at the bottom pool. I think its from shocking it when it was so hot.. Can anyone tell me what it is and how to get rid of it.. I vacuum and it puts it back in .

[21958]

Sounds like it could be dead algea which the filter has avery difficult time filtering out. One option is to vacuum to waste. With a sand filter what I have done is use a clarifier that gets added to skimmer and forms a gel over top of sand and helps it filter better. You will still have to back wash more often as dead algea is very fine.