How much chlorine loss is normal?

[dubbedout]

I've been testing my water nightly ever since switching to bleach. I've noticed that it seems to me that I'm losing chlorine quickly. Maybe it's normal but I wanted to run this past the experts!

Last night @ 9:40pm
FC - 14

Tonight @ 7:50pm
FC 9.5

I'm in AZ where it's consistently been over 110 degrees lately. My CYA (last time I tested) was at 117. The pool is crystal clear, but should I be losing that much CL in 1 day?

[Watermom]

How did you get a CYA reading of 117? The 'disappearing black dot' CYA test cannot differentiate readings past 100.

Did you add any bleach after you got the reading of 9.5ppm?

[dubbedout]

When I tested using the K2006 kit it was right under the 100 mark, so I took a sample to the local Leslie's and had them test it to get a better idea of where it was. They got a 117 with their digital test. I haven't added anymore bleach yet, I usually do around 9:30pm as thats when my pump turns on.

[Watermom]

Ok. Then, if you can, go out in the morning and test the chlorine within one hour of sunrise and report your reading. If you lose more than 1ppm overnight, then your chlorine loss is probably from fighting something in the water. Also, test the CC in the morning. How does the water look?

[dubbedout]

Water is crystal clear, and CC is always either 0.5 or 0. I just fought off some algae last week, thats when I switched to bleach. I'll test in the morning for chlorine loss overnight.

[dubbedout]

Ok so this morning FC is 9. Water still crystal clear. What's the deal?