I built a pool when I lived in Honolulu and ran it at CYA of 40-50ish. I wouldn't raise your CYA level too much or you'll have to keep a higher chlorine level - and bleach is a lot more expensive in Honolulu! (I could never get over how much Times charged for a little bottle of bleach - Big K and Walmart were the places to go, even though I hated both stores.)

I wonder if you don't have something else going on - like fighting some algae that's eating up your chlorine?