Chem,

You don't say how much ppm you lost during the day...only the ending ppm. I assume to be about 2-3ppm. That's not bad. I've been losing about 4ppm with a CYA of 30 so I recently upped my CYA to 50, hoping to slow my loss to around 2ppm.

The CYA level is ultimately your call. You can always add more but it's difficult to reduce.

I still see no reason to maintain your Alk outside recommended levels (80-120) but then, if it ain't broke.....