CYA added by trichlor tabs.

[sparkwatercleaner]

I would like to know how much it would take for two 3" 7oz trichlor tabs, added every week to a floater, to raise CYA levels up to 100ppm in a 10,000 gal pool.
Thanks.

[chem geek]

I would like to know how much it would take for two 3" 7oz trichlor tabs, added every week to a floater, to raise CYA levels up to 100ppm in a 10,000 gal pool.
Thanks.

Two 7 ounce (3") Trichlor tabs increase Free Chlorine (FC) by 9.6 ppm and Cyanuric Acid (CYA) by 5.8 ppm in 10,000 gallons. With this added every week it would take 100/5.8 = 17.2 weeks (around 4 months) to add 100 ppm CYA to the pool. This assumes you start with 0 ppm CYA and also that there is no splash-out, backwashing or other dilution. Evaporation and subsequent fill don't dilute since evaporation simply concentrates and doesn't remove any CYA.

Any particular reason you are asking?

Richard