Hello, All. On my 3rd summer with a vinyl lined ~25,000 Gallon Pool with Autocover. I have operated the pool per the TFP-endorsed BBB method throughout all operating seasons, and couldn't be happier with my results. Use a test kit regularly, and have been averaging ~.5 ppm loss of chlorine per day when unused/short use... Getting ready to leave for a 12 day family vacation- pool will be covered, and pump running 24/7. I figured this is the time to finally use the Hayward CL-220 Chlorinator that my installer provided, so I decided to run things overnight last night to confirm the Settings. My plan was to check Chlorine level at 12 hours, then 24 (which I never got to) and shoot for a setting that provided me with ~.5 ppm over a day.
The Hayward Manual suggested 10 3" Trichlor Tabs, and a setting of "3" on (with "10" being maximum Chlorine, "0" = Off). Of course, there suggestions are likely for an uncovered pool, so I decided to let things run with set at only "1" and measured my Chlorine levels (FAS/DPD) just prior to loading the Chlorinator. Starting FC - 0.5 ppm yesterday evening (90+ degree sunny day, kids and friends had been swimming all day). When I awoke this morning, I measured again and was shocked to see my levels were up to 4.5 ppm after only 12 hours of running. I turned the thing to "Off", and remeasured this evening (still at 4.5, with no pool opening/usage today, so at least "Off" is "Off" on the Chlorinator).
Does this sound reasonable, or might something be wrong with my Chlorinator? Does anyone out there have a ~25,000 G Pool + Autocover that could suggest some settings? I'm thinking I'm going to need to pool several of the Trichlor tabs OUT of the feeder, as it really can't be turned much lower... Only have a few days to figure this out (leaving for vacation Monday), and kids would likely be swimming so I don't can't have my levels going much higher in the short term. (Current CYA Level is ~25 ppm, as I've consciously let this remain low this summer knowing that I'd be using tricolor for a couple of weeks).