kday25;493950 wrote: Your calc and alk levels looks fine. Do you have a cal reactor? or are your water changes keeping your calc and alk levels in check? How heavy is your coral stock? When I had to start dosing, my
pH was 8.0-8.1,
alk was very low (3-4 dKH),
calcium was fine (around 400), and
Mag was very low (950). This is with a moderately high SPS stock in a crammed 50 gallon.
I got the BRS two part because I needed all three elements (plus pH) raised in my tank (water changes just weren't keeping up....or I wasn't keeping up with water changes, lol:doh

. Your case is different, you just need Magnesium.
So, IMO you really just need a good Mag supplement. Take your pick, I don't know which is better or worse. I used Kent Tech M to get rid of Bryopsis, so that and BRS are the only two products ive used.
Are these tests on your 75? or the 150 (in progess)? You'll prob need more than the small bottle of these supplements. I think you can get a gallon jug.
Hope this helps. :up: