water problems?

[astranotus]

Hey all..been a while...so here's my problem...I have a 275 mixed reef going..and every time I put a welso in or tracaphyllia in the display..they just shrivel away and die..my sps are booming..candy canes are doing good ..just about everything else is fine..fish keep disappearing..but now I see my zoas don't open and some green palys now are starting to look sickly..but there are 2 zoa colonies doing good??? don't get it...I checked Alk,cal,ph,iodine,ammonia,nitite,nitrate,phos...all fine??? Help....cant get a welso or trac to do good..

 

[dz6t]

ANy chance there are some sort of worm in the tank or one of your fish develops a taste for some corals? I used to have a purple tang that ate brian corals.

 

[astranotus]

Actually..I found the problem..corrosive metal from the light stand..had salt creep and became like paste and was dripping into the tank ..I knew there was salt creep there etc. but..havent been ontop of the tank lately...see...its about 6 1/2 up!! ha ha...thanks man.,..