Got a little lazy the last month or so and neglected the pool, since I was planning to replace a lot of the water anyway (I won a drawing to get free water 1Q 2013) to lower the CH. Anyway, the FC must have just dropped to zero and water was starting to get a bit cloudy when I started to drain.
Filled it back up and got the CYA 25-30ppm (pH 7.5, TA 80, CH 350)
Notes: I have not shown any CC throughout and the pump as been on high 24/7 and solar is running during the day.
7pm: Added 2 182 ox bottles of 6% measured FC of 8.5ppm ... I expected each bottle to add ~4.5ppm, so this seemed reasonable
7am: FC 6.5 ... clearly something in the water still, failed OCLT, added 1 bottle of the 8.25% should take me to ~11ppm
9pm: FC 6 ... hmmm seemed to loose ~5ppm during the day, added 1 bottle of the 6% bleach, should take me to 10.5ppm
10pm: FC 10.5 ... looks good
6:30am: FC 9.5 ... might have passed the OCLT, water looks great, had wife add 1/2 bottle of 8.25% @ 7AM and 1PM
9:30pm: FC 7 ... seemed to loose ~7ppm during the day, added 1 bottle 8.25%
10am: FC 9 ... did not test after bleach addition last night & sun was out, so not true OCLT, verified CYA ~25ppm, pH 7.8, added 1 bottle 8.25% and 16oz MA
10:30pm: FC 6.5, ph 7.5 ... seemed to loose ~7ppm during the day, added 1 bottle of 8.25%
10am: FC 9 ... sun was out, so ignoring ~2ppm OCLT
I need to verify that I am actually getting ~4.5ppm rise from the 8.25% bleach and do a true OCLT tonight to see if I pass. The water is very clear and there is no debris in the pool.
I am surprised that I seem to be loosing 5-7ppm during the day which is about 50% of what I am starting at. Is that 50% loss pretty normal for the low CYA? I guess I was expecting to only loose 3-5ppm.
After the OCLT, I am going to start raising the CYA closer to 50ppm. I am thinking that maybe the CYA is a little lower than I think and that is why the daytime losses are so high. Pool looks great, so I am thinking my pseudo-shock process is complete ... OCLT should confirm.
Any thoughts or care to confirm my thinking?