How much CYA does a typical 3" (8oz) Trichlor puck add?

[napkin41]

Hey all,

After several CYA tests to make sure I wasn't crazy, I've determined my CYA is pretty low, around the 20-30 range.

Rest of the readings, because I know you guys will always ask:
FC: 6
CC: 0
pH: 7.5
TA: 80
CH: 300
CYA: Call it 30

I've been using tabs to save on bleach and bring my CYA up a bit for the summer. The bucket of tabs is not very detailed about chemical composition.

Does anyone have any rule-of-thumb information regarding about how much CYA one 3" puck will add? I even measured it on my wife's food scale and it came out to about 8oz if that helps. (Don't worry, I had a wash cloth under the puck and zero'd it with the scale, the food scale is clean, lol.)

Thanks!

 

[JoyfulNoise]

You can use Pool Math to figure it out as it depends on pool volume. In your 12,500 gallon pool, one (1) 8oz trichlor puck (assuming it's 99% trichlor and not some multi-component puck) will raise your CYA by about 3ppm. The rule of thumb is this -

For every 10ppm of FC added by using trichlor, your CYA will go up by 6ppm.

 

[napkin41]

For some reason I had trouble asking Pool Math that very question. Thanks for breaking it down for me!