CH = 400 too high for a new gunite/pebble pool?

[joelq]

Hi all - we have a new 12000 gallon IG with SWG, started on August 1st. I've been testing at least once each day with a Taylor K-2005, and below are my numbers as of 30 minutes ago:

FC: 4
CC: 0
TC: 4
pH: 8.0 (as it always is in the morning, so I have to add 40 oz of muriatic every morning).
Alk: 90
CH: 400
CYA: 55
Salt: 2900 (according to the Aqualogic PS-8), 3200 (according to Taylor salt test kit)

I noticed that my CH has risen since start-up (was 140 at startup, 350 ten days later, and now 400.) My Aqualogic manual says the range for my CH should be 200-400, so now I'm at the high-end of that.

I've read many posts saying it's bad to have too low calcium for a gunite pool, but what happens if it's too high? Is 400 too high? What's causing it to keep rising?

Thanks everybody!