So this tank has been up and going for over a year and up until about six months ago I had no problems. I moved the tank and since have had major problems. No coral seems to want to live and I can't figure out why. Salinity is around 26 ph 8.3 no trace of nitrates,nitrites etc. The only thing I haven't tested for (because I can't find the tests) are calcium and alk. I use Ro water (brand new unit) an don't have a sand bed. Roscoe had been holding corals for me for about 6 months and one was dead in a day once it hit my tank. Clams and fish are fine, SPS not so much. Lighting is a 250 watt metal halide. Equipment is deltec mce600 skimmer, waveysea for return and k3 for movement. Oh one more thing this is a 40 breeder. If I can't figure this out soon I'm done!