njbcpool

I need help with a new problem after uncovering my pool a few days ago.I was surprised to see a purple chalky residue or stain on my liner,steps. I converted to a salt system last year. When I winterized I did the usual routine, liquid shock and algaside. I asked my local pool guy if he knew what the problem was and he had no idea.This purple stuff wipes off easaly, but its going to take hours to vacuum. Can anyone help me out Thank You