Rich,
Is your BRS Mg magnesium sulfate (epsom salt) or magnesium chloride? I used BRS Mg Chloride and epsom salt (Mg sulfate) to whip the bryopsis in my tank. That may be why some folks have good luck with Kent Tech-M - it has both Mg Chloride and Mg Sulfate but a higher concentration of the Chloride. HTH.
-Ed
P.S. Thanks for your service! Glad you are home and safe.
Custom Acrylic 180g RR, acrylic sump, 45BR frag tank, 18g fuge, 250+/- lbs LR, Euro Reef CS8-2, 10x39W T5, softies, LPS, and a few SPS.