OK the tank has been going since mid April. I have been adding B-Ionic Calcium since the start of the first coral. At first it was only 20ML per day. My calcium after 4 weeks was still under 300

So the LFS told me to increase it to 30ML per day. So now after two weeks of this I am only up to 330

I have read here, there, and everywhere that with the corals I should keep it at least 400!! Any ideas? I don't want anything to happen to the corals.
Thanks
Kathy