I have a white residue above the water line all around the pool. It looks like calcium deposit, but does not react to acid. It does seem to clean off with just water, but reappears a day or so later. Could it be salt from evaporation? If so, is this a problem?
Here are my numbers:
Air Day 72Â°F
Air Night 45Â°
The pool is currently heated, but I will probably cut back on that soon.