Hey guys, long time lurker first time poster. This is only my second season owning a pool. Last year I had the water balanced all season and it was always simple and easy. This year I have everything balanced, ph, cya, Ch, Alk, EXCEPT I cannot keep chlorine in the pool. I have an in line chlorinator directly in line in the return line to the pool, no black hoses, last year set to 3.5, this year set to full and I am always about 0.5 FCL, with the TCL always matching or within . 1 of the FCL. I have been tested for phosphates and they are low, under 100ppm, and have been tested for nitrates and there are none. The water is crystal clear, no visible algea anywhere. If I shock the pool the FCL will come up but it's gone back to 0.5 within a day or two. I do not have a lot of sun on the pool at any point during the day.
I'm at a loss here and so are the pool stores in my area. One major chain keeps telling me to add 1lbs of shock which clearly doesn't work. The other mom and pop store suggested I slam the pool so I put in 6lbs of 70 percent chlorine shock. It raised it to over 10ppm, I'm not sure how high as the tester only goes that high before it just says high. It took just over 24 hours to drop below 10ppm, and at 26.5 hours I'm at 8.68ppm.
Latest water test before I did slam, my test on left, Leslie's on right
Fcl 0.40. Leslie's 0.31
Tcl 0.79.leslies 0.31
Ph 7.1. Leslies 6.7
Alk 113. Leslie's 81
Ch 52. Leslie's 266 - I belive my reagent is expired
Cya 59. Leslie's 79
Anypne have any insight here?
Pool details
24200 gallons
Vinyl
Hayward de filter 3620
Hayward h250 gas heater
Hayward cl2002s chlorinator