I accidentally spiked my Mg 800ppm in one dose in my sps tank, nothing seemed to mind very much except my sanity
. I also almost melted the bottom of a bucket out the first time I bought anhydrous Mg. I remember my chem prof telling me to add chemicals to water, not water to chemicals, but i didn't listen! Do you mind telling us how high you think you dkh got and how much you raised it? I'm kinda curious what you got away with, assuming you haven't lost any corals.
FragIt Dan