Just wanted to share my good experience with bleach as opposed to pucks. It wasn't so much that the pucks were increasing my CYA, but call me crazy, the pucks seemed to lower my PH almost daily, and I just couldn't seem to keep algae from forming. So........I switched over jugs of Walmart bleach, and with the same FC level in the pool as with the pucks, I almost immediately noticed that my PH was more stable and I had no algae forming. My PH was dropping from 7.5 to 7.2 daily with the pucks and now it's been the same for almost 4 days. It seems to me that a stable PH of 7.5 has kept algae from forming. Yes the bleach is a little more expensive, but I'm not dumping in Borax daily either. The bleach might actually be cheaper in the long run. Signed, Happy Camper