How Much Chlorine loss Is Normal

[DCR]

With a CYA of 40, even in full sun, a drop of 4-5ppm seems like too much. Is he filtering the water during the day? Also, if testing shows any CC I would bring that pool up to shock level and keep it there until the overnight Chlorine loss is no more than 1-2ppm.

He is running his pump from 7:30am to 11:00 pm

[DCR]

He checked his cl loss over night, and found that it was not going down at all, so it seems to me that running the pump during day would increase the cl loss, so I suggested he run it only at night, besides 15.5 hours seems excessive. Please let me know if you agree with my suggestions or is there something I am over looking or am I just flat wrong.

[poolrx]

I think there is a lot of variables and don't think your flat wrong. Cl loss should be minimal at night b/c no sunlight. I run my filter during the day b/c I find it heats my pool more effectively by circulating the water while the sun is out. My cl was 7ppm on Sunday and dropped to 2 ppm today. But thats just my pool. Since the cl level didn't drop at night I would think that there is minimal to no cc or it would drop at night as well trying to fight whatever was in the pool. Have them check the cya level again. Does he have Ben's kit or get the results from a pool store? A lot of times the pool store can be inaccurate. As already mentioned, a cya level of 40 should keep the cl loss to around 1-2ppm per day.

I agree 15 hrs seems a bit much. Again depends on the pool though. My pump runs from 9:30am-7pm.

[CToon]

Unless there is a need to run the filter , ie cleaning up after an algea bloom , 15 hours is not beneficial.

What happens normally is the stuff in the pool either sinks or is suspended. The stuff that sank isnt going anywhere but the bottom. The suspended material will be picked up by the filter . Eventually , when all of the suspended stuff is cleaned out , clean water is being filtered all over again.. not beneficial

Actually , cycling the hours the filter runs is most beneficial , say something like 6 hours on 6 hours off 6 hours on etc etc