I'm new to the forum but I've been reading posts for a couple years now - thanks to all for letting me eavesdrop.
I have a question: Is my pool's bad plaster is a factor in having to dump tons of chlorine/chemicals in to try to control black algae? And, should paint/replaster the thing to save chemicals and hassle on trying to control that black algae?
I have to confess my pool has been a bit of a headache for me and I've actually been contemplating turning it into a sunken-patio-thing or decking over it or just ripping it out and filling it in! It's an oddly-wavy-shaped 15x40 pool, with a 9-foot deep end. I've been battling black algae and green algae on the walls ever since I filled it two years ago. Even adding silver solutions and raising the chlorine really high (and brushing a lot, and rinsing the DE filter over and over) don't resolve the issue in a very satisfactory way. The water gets clear but the walls have a persistent presence of the black algae growing like a dotted spiderweb of evil.
The pool is probably 30 years old and may have had a previous re-plastering job done long ago. It sat empty for about a year in 2013. The current plaster is pretty bad, which I suspect is a wonderful host for the black algae to get in deep. A while back I drained out the attached spa which has the worst problems on the plaster. I took the back end of a claw hammer and knocked around a little bit on the small chunks of partly delaminated plaster. The black algae was growing *under* the plaster, too. Not having the time to attempt whacking away at the whole spa and starting a replaster right then and there I just did a quick acid-wash/brushing and refilled it. That has had zero effect on the native black algae population.
Thoughts? Is a highly pitted / delaminated plaster pool going to be an algae nightmare until I fix the plaster, or is the plaster more of a cosmetic issue and my problem is mainly a chemical one?