Zero FC Pool is crystal clear

[Hurricane1938]

The FC and CC comparisons that you need to note are the numbers taken an hour after the evening dose of bleach and the readings taken the next morning within two hours of sunrise. Seeing what kind of overnight loss you have is an essential piece of information.

Several nights ago I added ~9 gal. of 6% bleach. Embarassingly, with the high levels of FC, I ran out of the reagent to check FC! I haven't added any bleach since then.

Last night readings: Temp 78F; FC 7.4; CC 0.4; pH 7.5; TA 130; CH 170; CYA 75

This morning FC 7.2

Am I right to be encouraged by the steady (within measurement accuracy) FC level?

CYA level seems to have declined slightly (9 days ago it was ~75-80). My Chlorinator is turned off. Will CYA gradually come down if my FC is coming from bleach and not stabilized tabs?

Thanks again for your help, it really is appreciated!

Peter

[PoolDoc]

Your CYA will drop ONLY when water is drained from your pool OR when algae+bacteria 'eat' it. You don't want the 2nd option, since some of the time, the bacteria 'poop' ammonia, instead of nitrogen gas.

So, you need to be careful to maintain Best Guess chlorine levels. Other than than, so long as your pH is in range, all should be well.

I would recommend keeping your pH in the 7.0 - 7.2 range, till your TA drops below 110 or so.