Frank I've always run my ALK at 12 as long as I can remember. 570 CA is down from a month ago when it was 650. Clams love it and grow like MAD!! I'd prefer to keep the CA down to around 475. I'm getting there.
The key to ALK is consistency whatever the number is (within reason). The one thing I finally got under control is MG. I could never get it high enough. Went with a small amount of dolomite in the CA reactor setup and bingo, got it where I want it to be and steady.
Tank is looking up finally! Rough tank winter this year. Taking down the nano tank. Most of the coral is gone. Fish next, then rock etc etc. Hanging on to the gear though just in case.