Question regarding chlorine loss

[jurmanji]

I'm in Los Angeles, so lots of sun/heat. I have a 1000 gallon in ground spa that pours into a 120 gallon basin. There is a cover on the spa but not on the basin so, from 9-3 everyday the pump runs and so does the waterfall.

I followed the sanitation directions and currently CYA is approx 30. Everything else is balanced.

How much chlorine should I expect to lose each day, and when should I worry I'm losing too much?

Thanks!

 

[BuckeyeChris]

How are you testing the FC, and can you post the actual results?

 

[jurmanji]

With a taylor kit so the measurements should be accurate.

for example went from 12 to 11 overnight then during the day down to 6 (measured around 8 am and 2-3ish)

 

[pooldv]

I would raise CYA to 50 in your situation.