Tabs in skimmer valid way to raise CYA?

[Watermom]

There is no way to say how many days it will take. I can tell you this, though. Trichlor tabs add 6ppm of CYA for every 10ppm of chlorine that is added. Please make sure that your trichlor tabs do NOT have copper in them. You do NOT want copper in your pool. It is copper that stains pools and turns blonde hair green, not chlorine like most people think.

[AnnaK]

I have an inline trichlor tab feeder. I run it exclusively at the beginning of the season, i.e. with the dial set to 'full', and it takes several weeks before the CYA goes from 0 to 50. With it set this high it puts far more chlorine in the pool than necessary. My pool is ~12,500 gallons. When I set the dial do 1/4 the tabs maintain 5 ppm FC at all times, and that's with the pump running only 6 hours.

I run the feeder full blast during startup when the water is still too cold to swim. When I can measure CYA at around or near 30 ppm I add granular CYA to get to around 40 ppm and decrease the flow on the feeder to 1/8. At that point, because it's not putting enough chlorine in the water, I start adding bleach to sanitize but keep the trichlor at a very low level to maintain CYA which gets diluted from splashout and refilling.