well to the best of my knowledge i think that i was pretty dumb in the fact that i had a tank that i had as a refugium and then turned it into a reef tank without removing the mud . for some reason that i really dont know it seems that i mad a big mistake because it took out 3 choati leopards , red margin fairy ,potters ,two bipartius, two black leopards ,one vermiculate ,and two tamrin wrasses in the last four months and i now have changed the substrate and have three wrasses in the tank . a yellow tail tamrin,radiant wrasse and a china pearly black backed wrasse so lets see what happens now . i really think that the mud had something to do but nobody has been able to tell me why it would . the wrasses all were divers and nestled in the sand but never suffocated in the mud and never shown any signs of wounds but just died , eating well ,fat ,and boisterous the day before death . all params were good but my temp was 80 which is a bit high for my liking so i have sinse lowered it to 76. the water didnt have anything to do with it either because i have a common sump and suffered 0 losses in the other three tanks during this time . just the one tank that had the mud so IMO it was the mud but there is no real proof to base a conclusion on at this time ................................... any ideas ?