Kent Magnesium is doing nothing to my bryopsis, I have had it up to 1500-1600 for 3 weeks and it is growing just the same. Will h2o2 hurt my corals if I dose? I have mix of SPS lps and all are healthy. I have been debating replacing my rock with tbs rock. Any negative affects to replacing rock and sand in an established tank (8months old with stable parameters and good growth in SPS) with a very shallow sand bed?