Every reef tank likes levels diff. Some range 30 plus or below. For example my ph stays around 8.1-8.0, corals and fish have been doing fine. That's were the tank is the most comfortable for the ph, etc. I would not go over 500 on the calc and 1350 on the mag. Then again your levels can be a little lower. I have alot of sps
corals, and mine like the calc about 450, and 1250 for the mag.