If those are truly accurate readings of your parameters, nothing, not a freshwater dip, not a peroxide dip, is going to save your corals. Before you do absolutely anything you need to do a massive water change and stop dosing the Kent essential elements because as stated is almost just a calcium buffer. The reason you are having this problem is because you have been dosing without testing. What is your mag at? I was thinking that the calcium would precipitate too but I think if the mag is out of whack it may allow the calcium levels to be super high.