I’m sorry if this is posted in the wrong forum but over the last 3 months we lost (in order) 2 plate corals, a trachypylia, colony of birdsnest, an acro frag, 2 meteor shower montipora frags, 2 Superman montipora frags one head of torch (other head seems ok) and now starting to lose an acanthophylia and Duncan’s. All zoas, leathers, gsp and clove polyps seem fine as does an acans colony And another large torch colony. All fish, snails and shrimp are fine. the tank is a year old and these corals did well for 6 months and were showing significant growth until the die off. all parameters are stable and we haven’t changed flow or lighting. we have a trident and this reads pretty stable with alk around 8.3, ca around 420 and mag around 1400. Dos controls ca and alk. We don’t add trace elements. Salinity is 1.025 And we use Red Sea blue bucket. Temp is 78. Nitrate and phos were near 0. There are no visible diseases (no flatworm, jelly, etc). We have no algae. We have some brown dust in a few areas on the sand that looks like the diatoms we had when we set the tank up. Rodi reads 1 in, 0 out and media is a little less than a year old with about 800 gallons used. We’ve asked the Lfs for help and theyve come out a few times, done a cleaning and feel it is dinos. We don’t have any bubbly, stringy slime but they feel the brown dust is dinos due to the low nit/pho. We have increased feedings and started dosing nitrates. I’m going to get an ati icp test but am bewildered as to what happened. The tank was thriving until 3-4 months ago…