I have a 250 gal saltwater setup with 150 lbs of live rock, 160 lbs of reef sand, 250 gal sump, 36 w jebo uv sterilizer, and now almost no fish (2 damsels and a six line wrasse) So...this is the story, about a month ago the uv sterilizer I had, developed a kinked hose and my fish at the time(hippo,sailfin,bristle tooth tangs,red lip blenny, royal gramma, formosa wrasse, and a harlequin tusk) began developing ich. When we diagnosed the problem with the uv sterilizer, I ordered another which promptly broke. In the process of getting another one almost all of my fish died. I have had this tank setup for 4 yrs, everything even survived a move and still thrived. With the wipeout of my tank I took the opportunity to replace the crushed coral with reef sand (I left some crushed coral in the tank to allow it to cycle although it may not need to). Now, no matter what fish I put in there, it promptly dies. I got a tenneti tang (I think that's how you spell it) after the crash, but before dying he developed spots all over his body, like someone beat him up. The last one to go was the harlequin, he appeared fine, but began developing a mucous that covered his entire body and then like all the others he died. This is so frustrating I haven't had any problems until this, and now I can't get the tank up and functioning again. Any sugestions as to what I need to get or what I'm doing wrong?