Draining to Lower CYA

[glewis29]

Nitedr, regarding your CYA level, once you get the pool under control, running a higher CYA level will actually lead to less chlorine use due to solar degradation than the 40-50 you were shooting for. The downside is having to run a pretty high FC level if you need to shock and it won't drop as fast (because of the protective effects of CYA). Honestly I don't think the higher FC levels a major problem myself aside from it making the pH test less accurate because the chlorine is not actually free, it's bound by CYA. So the active chlorine you have is the same as at lower levels, you just have a much larger buffered reserve (which in theory should make SLAMing much easier)

For clarification, by higher I meant 80-90, going much above that and I think everyone here agrees the cons start outweighing the diminishing returns from the pros.

 

[Nitedr]

Update....

So i got home yesterday afternoon and tested FC which came to 20 and CC at 0 (4 FC loss in about 11 hours). I read in other threads that normal FC loss is 2-3 ppm per day. Am I correct to assume that since my FC concentration was higher I will experience a higher than average FC loss per day until I reach a normal range?

Also, When is it safe to swim?

 

[tim5055]

Update....

So i got home yesterday afternoon and tested FC which came to 20 and CC at 0 (4 FC loss in about 11 hours). I read in other threads that normal FC loss is 2-3 ppm per day. Am I correct to assume that since my FC concentration was higher I will experience a higher than average FC loss per day until I reach a normal range?

Also, When is it safe to swim?

Yes, FC above your target for CYA will have a higher loss as more is not protected (unbound) by CYA. The only true test is the Overnight FC Loss Test (OCLT).

It is safe to swim as long as you are below shock level for your CYA and the water is clear enough to see the bottom if someone was in distress there.