I'm new to the forum, but have been lurking and reading for awhile. I have a 20,000 gal saltwater pool. All the chemistry parameters and values seem to be at acceptable levels and the water looks great, although the chlorine levels continually seem to be on the low side despite running the salt water generator at a high level and adding chlorine shock somewhat regularly.
These stains simply won't scrub off. I would love some feedback on how to address this issue!