Reef Crashing

[Paul_N]

Have you had coral in the tank since the beginning (for the last 2 years)? Also, is it only new coral you are adding to the tank that are dying?

 

[sanchoy]

Ok calm down.. deep deep breath..

-check parameters (like most have said.. big ones are Alkalinity, Calcium, Magnesium... Then Phosphate and Nitrate. I would even do Ammonia in your case).
-Visually check all bulbs for metal rust/ or rust that may have accidentally leaked into your system.
-visually check inside sump/ and tank for foreign objects that may have fallen in there ( i had a buddy who had a mouse die in his sump,, crashed his entire tank).
-Check TDS on Rodi water.. make sure the source is good.. Then do a big water change.

If all is well. then more then likely something accidentally entered your system. Sprays (air freshners/glass cleaners) can be a factor. Paint odor is another.

 

[ron garnett]

I just took all of the live rock out of my tank and the first thing I discovered was a two inch wide stone crab. He was probably responsible for the immediate disappearance of my peppermint shrimp I introduced several months ago. While scooping him up with a net I discovered a rusted screw. I'm wondering if the screw might be the culprit. One screw in 240 gallons of water. I don't know if that's enough to kill coral or not. It could explain why my fish are doing fine (not as sensitive to heavy metal) while the coral suffered.

 

[GR808]

Floating bags and placing corals on substrate after acclimation.

floating the bags will only acclimate the temp for your livestock. You should probably drip acclimate or add some tank water gradually to acclimate your tank parameters as well.
good luck