how much CYA will a 50lbs of tri clor add?

[chem geek]

That's pretty darn close. 50 pounds of Trichlor is equivalent to 27.8 pounds of CYA in terms of its CYA content (i.e. these stated amounts both raise the CYA by the same amount) -- 332.8 ppm CYA in 10,000 gallons -- obviously way more than anyone would want.

[aquarium]

Yeah, I rounded off. I asked DuPont about this last year and they said each puck was 56% CYA. 50 pounds times 56% is 28 pounds.