I am accumulating two or three white stains on my fiberglass pool every day. Have been shocking for the last week. 2 lbs of HTH shock every night, and can not keep FC up.
I have been mixing shock powder in water before broadcasting in pool, and following up with pool brushing so as not to have any undesolved powder laying on bottom.
Any ideas on the stains. I want to prevent as much as possible. I have brushed stains with no effect.
Latest test read is:
PH - 7.3
TA - 140
CA - 40-50