Hi everyone! This is a great site. I wish I'd found you years ago! I'm the original owner of a plaster pool and have always followed the advice of the local pool store that is affiliated with the company that built the pool.
For the first six or seven years, everything was fine with my pool. I treated the pool with 3" triclor tabs, weekly super chlorination with granular chlorine and bi weekly pro60 algaecide.
Then the problems with algae began. Although I had crystal clear water, I was getting green algae growing in the corners of the steps, around the pool light and in the skimmer intake. I would scrub it and it came off easily, but always came back. Chlorine demand was incredible. I would shock with huge amounts of the granulated chlorine and the next day it would be gone. This lasted a couple of years (I know, I should've acted sooner!) the pool store was useless in terms of advice. Finally, the pool company treated with copper algaecide and I thought all was ok.
In the meantime I switched to cal hypo shock because my CYA was very high. Of course, that in turn drove my CH up to 480. Then this summer, I inadvertently let the chlorine level drop. My chlorine dispenser stopped working and I started to notice black algae. Not much, but it was there. I scrubbed and scrubbed, used a silver algaecide and when the algae went away, I put a sequestering agent in for fear of staining. The black algae came back, still slight, but there.
After doing a lot of reading on this site, I decided that I needed to bring down the CYA and CH and drained 1/3 of the pool and refilled. Prior to doing that, CYA was well over 100, but this brought it down to 90 and CH to 360. Not low enough. Just this evening, I drained another 50% of the water and am in the process of refilling.
My last readings were
My plan is to retest the water once the pool is refilled, SLAM with 12.5% liquid chlorine and brush it like mad (stainless steel brush). Thereafter to use the TFP method going forward.
My question to all of you is 'does this make sense'? I've been through so much with this pool the last few years and I want to get things under control once and for all. Is there anything else I need to consider ?
My pool company, who I am now furious with, came out to advise and told me I need new plaster, $7000 worth! The plaster still looks really good, to me. It is a little rough all over, like fine sandpaper, but I think this might be a bit of scale from the high CH. It is still white and looks thick. The pool company said I need new because when they brushed it, white dust came off in the water. Is that scale or I'd the plaster degrading? I want to ensure that I have exhausted all other options before re-plastering, so I'm spending the next few days on the above plan.
If you have any advice for me I'd be really grateful to hear it. Thanks so much! Sorry for the very long post!