I have a fiberglas pool and I'm seeing a dark color waterline ring.
I'm scrubbing but it still remains,
the source water is filtered thru carbon at 5 micron, so it not the source.
What's the cause?
What to use to clean it off?
I'm scrubbing but it still remains,
the source water is filtered thru carbon at 5 micron, so it not the source.
What's the cause?
What to use to clean it off?