Don't continue with the B-ionic at this point. Two-part supplements are really intended to "maintain" your calcium/alkalinity levels at a good point - it's meant to replace what the corals are taking out.
You need to get your Ca
levels up (probably by using Turbo Calcium) and stabilize your alkalinity before you start doing a two-part dose. As previously noted, you're going to need to know your alkalinity (either in dKH
or meq/liter) before anyone can really tell you how to modify your tank chemistry. However, with Ca
that low, water changes alone are not going to be enough to get your Ca
up in the low 400s.
Once you know both your Ca
, then check this article out...
Once you get your Ca
levels where you want them, then you can start with the B-ionic again.