I wish I had found this forum before I Opened the pool this summer!
I have a fiberglass pool and therefore it is not to be drained unless the water is pumped out from underneath (huge hassle), and my cya level is high at 80.
I live in Toronto so the pool is only used 3 months per year and this is my second year. The pool has a copper ionization system and a puck feeder. Due to a bylaw here a saltwater pool would have cost a crazy amount given the sewer access at my house (don't ask the bylaw is too strange to explain).
My question is how much can I lower the CYA levels by exchanging a several inches of water each week? Is liquid chlorine safe for fiberglass pools?
Pool is clear, I just shocked the pool to re-establish chlorine after these test results
Lab results: tc .6 and fc .3