I thought i was an expert - built and serviced pools in my younger days, and have owned 2 in the past 10 years. My current pool is a SWG system (Hayward) and everything was dialed in perfect last year - pump ran about 7 hours at night and 2 hours during the day, chlorinator at 65%.
This year, all was good in may with the same setup, but for the last 6 weeks Free Chlorine (measured by OTO or DPD) is reading close to zero - even with chlorinator at 100% for 12 hours. Even running for 36 hours straight and i only get up to 1ppm. I thought it was the cholorinator as i pulled water of the return line and saw low readings - but the chlorinator numbers (V/A) look good and bucket test shows it is putting out chlorine. I am using the Taylor DPD test kit - and i have run out of ideas. I can keep throwing in a few cups of granular every few days, but that is irritating.
CYA ~ 80
FC = 0 (slight pink from above so maybe 0.2)
TC = 0 - (unless i pull water right off the return line - then it shows FC 1.0, TC 1.5)
PH = 8 - yeah a little high, but shouldn't be a big deal
Phosphates - 0
CH = 250
I am still leaning towards the SWG not putting out enough CL - but no one (even Hayward) wants to tell me what it should put out.
I have a T-15 cell on a ~20K gallon pool. I wound up paying for a service call because the cell made bubbles.
Any ideas to rule in or out the water or cell are appreciated...