I would leave the 55 CYA alone. I've battled very high CYA (120+), and you can succesfully keep the pool clean and clear, even at very high levels by following the best guess chart. In my opinion, if it ain't broke, don't fix it. Especially with the issues it sounds like you have with fill water.

Have you considered a SWC unit? You're at the right cya level for one, and you won't have to lug bleach anymore...