Thanks for the quick response. We inherited the setup when we bought the house 2 years ago which includes a Pentair chlorine feeder (320). It's convenient and trouble free for the most part. I think I'll throttle back the feeder and start using LC or bleach to maintain my FC. I think water additions due to evaporation may make the CYA come down or at least not get any higher. The pool looks really good right now, but every spring I'm fighting green algae. The pool is open all year. I think because the system only runs for a few hours a day from Nov. to Mar. the FC drops while still having high CYA. Now that I have my Taylor test kit that was recommended, I can figure the algae thing out.

The CYA should also drop because I have a leak. I have the bucket test results and I'm waiting for some test plugs/inductors. I'm adding about 1 inch per day due to evaporation/leak loss. I'm pretty sure I know where the leak is - return line - which is consistent with the pump on/off bucket test results. I was scratching my head about it until I remembered that I had several pallets of pavers delivered about the time the leak started. I had them dropped near the pool and they went right over my return line with their huge machine. Live and learn. I'm going to verify with a pressure test before I start digging. I'm thinking about replacing the 1-1/2 inch return line with 2 inch between the filter and the water valve for the in-floor system. The filter has a 2 inch fitting but the valve is 1-1/2. (Master Pools)