My P.O.P. is gone. need help again

[chem geek]

If there is no sunlight and no bather load and an FC that is roughly 10% of the CYA level, then 24-hour chlorine loss is typically under 1 ppm and sometimes under 0.5 ppm, but the exact loss depends on temperature. In my own pool at 88ºF that number is on the order of 0.7 ppm FC per day (with normal bather load and the pool cover open 1-2 hours most days and longer on weekends and 40 ppm CYA, the loss is closer to 1 ppm FC per day). For residential pools that usually have a low bather load but that don't have a pool cover and are exposed to sunlight, the usual daily chlorine loss is around 1.5 to 2.5 ppm for most pools though some may be higher if there is heavier organic load such as blown in pollen, etc. This loss rate is also a function of the CYA level where higher CYA levels (with proportionately higher FC levels) lose less chlorine.

[shub_31]

all I can say is my cya is 100 and starting of with a FC of 10. Introducing a kid or kids with suntan oil and a dog and sun my pool will be down to 5ppm in several hours. Ive bought so many jugs of bleach im losing track of the money im spending. O well ill see what happens the rest of summer and hope next year is betterm thanks for th great replies

Scott

[chem geek]

A dog is equivalent to many bathers and if the kids urinate in the pool then that can also create a large demand, but it sounds like this happens every day for you, not just for such one-time incidents. Are you saying that if kids and dog do not get into the pool and there is just sunlight that the FC doesn't drop or are you saying that it does? I'm trying to understand if it's specifically the introduction of the kids and dog that are causing the drop.

[shub_31]

Theres been very few days that no one has been in the pool. Its been 2-3 months since I have covered it. The other day was the first time covered. It wasnt a very sunny day and no one had been in it. I think it dropped 1 or 2ppm in 11 hours. If I remember correctly it has dropped uncovered full sun with no one in it. Its yo yoing too much based on replies. Just last night it was 9ppm covered and this mourning 8. No one in it yesterday except 2 frogs. the kids get out to go pee and so does the dog. It does drop sharply when we are all swimming. I would have to put bleach in it all day to maintain 10ppm