I have mixed sps, lps, and softies in my 150. Everything is doing good, acros, montis, bubbles, xenia, zoes, ect, EXCEPT my leathers, neon mumps, yellow, other fingers and tree corals (there is plenty of water flow and they have done good in the past). Water measurments were off initially, then i readjusted everything back close to specs.... Kh 110, Calcium 430, Ph 8.3, and no ammonia, nitrates, nitrites (I currently dont test for phosphates or treat them because I dont have much of a green algea problem, tons of purple corileen <sp?). I just recently did a few 15 percent back to back water changes (Might have adjusted water too quickly?) .... Its been almost a week now and the only problem I can think of is my magnesium. I bought a test kit and tested it. It reads very low, under 100ppm. Could this possibly affect the leathers? I tried to add some kent magnesium additive and it seemed to get worse. I am using the Salifert magnesium test kit and am sure im doing it right. Unless the test isn't working properly and I have way too much magnesium and am just burning my leathers. Im not really sure what else could be wrong. Any help would be great.