You are right on target! You can try to pre-dissolve the CYA, but it still takes a long time. You can also put it in a sock or, better, a leg off pantyhose and tie it to the ladder, preferably in the return stream. It's still going to take 48 hours to a week to get it up to target. Make 30ppm your first target and then adjust to 50 if you need to. Always easier to add stabilizer than remove it.

Carl