A while back, Ben had mentioned keeping higher CYA levels for pools using bleach to avoid frequent additions. 50 ppm CYA may not be enough to do what you want, you may have to end up closer to 60 - 80 (!) to be able to hold the Cl. I know with my pool, even with keeping the CYA in the 40's once the sun starts beating on it all day, it will kill off the Cl pretty good. Wasn't that unusual for me to lose about 2 ppm/day.

Keep us posted on how it goes.

Michael