Just a thought but have you tried taking a water sample to one of the LFS or a friend just to double check that your test kits are reading correctly? If it is an option can you move your corals to another tank (friend or spare) until you figure out what is going on? I know that one time I had a problem with some of my SPS and it turned out (I think) to be that one of my heater was leaching current into my tank from a loose wire on the connection. It was a very tiny amount but just enough to feel and I had 3 coral RTN before I took it out. Like I say - I'm not sure that was it but the RTN stopped when I removed the heater.

I used liquid reactor with a lit sump without problem..

Do I understand correctly that you slowly filled the tank over a period of weeks? were the halides on during the weeks it took to fill the tank? Just a thought that possibly the corals were damaged (burnt) during this time... probably not tho.

Green skeletons to me would mean that the coral tissue has been dead for some time and algea has had the oppurtunity to grow on the skeleton this would be a STN situation... do you notice a recession of tissue at the base of any of these corals before they lose thier tissue?... I am just thinking out loud here if anyone has more knowledge than I please chime in

What was your Ph tonight?
Did you add liquid reactor? if so what was your Ph 1 hour after?
Your sure their are no red bugs? once these little bast#rds get into a system they are usually there to stay?

hope you get this problem figured out soon :mrgreen:
Dan

I find that for some corals, the color is a dark green when they rtn and others are white. It seems that acropora mostly from bali for me always turn green when they die. Mind you I've only ever had two instances where this has happened.

They look like this http://www.canreef.com/photopost/sho...sort=1&cat=504. (Sorry I can't "right click" to get the appropriate photo info on my mac.) For me its only been the Bali acros that are purple with blue tips that have this coloring underneath. In this particular picture the RTN happened over night, so I'm very sure that it isn't an algae growth.

pH went down a bit, lowest point was at 7.9 for the evening.

I've been watching and watching for red bugs, but can't see anything. I am going to be treating my corals shortly regardless. I only ever saw them on one coral before it RTNed and I haven't seen them since.

Tonight I'm going to start back with liquid reactor, and hopefully that should start to get things back on track.

The more I think about the situation the more I think its chemically related. None of my fish or invertebrates are suffering in any way I can see. All my soft corals are growing like weeds, and clam death aside (as I believe it was just a bad coincidence), things seem to be flourishing.

Everything seems to be fine until something begins to RTN, once it begins, that particular coral is gone before anything can be done. And since nobody knowns what triggers RTN, I, as I'm sure many others have, feel helpless.

Focusing on the RTN as a result of a water quality issue then seems to be the next logical step. My corals are getting enough light, they are actually recieving about 2 hours less per day of MH exposure then they were a couple of months ago. We regularly correct our dKH, probably about every other week. Calcium is above where it should be so we've stopped dosing for the time being. We started to begin to drip Kalk, but tapered that off until we can find out the cause of this issue. I feel spriulina, frozen mysis, krill, and formula-1 pellets. I do wash the frozen foods before feeding them as well.

What about if electricity was leaking into the tank? Perhaps at such a low level that it doesn't bother the fish?

I've read this many times and seen it a few, so I will try and explain from my limited experience.

When an acro / sps starts to RTN, often it becomes a tank event. With no real explination. Your best course of action is to frag the RTN'ing coral as soon as you notice and get the dieing tissue out of the tank. Also you want to frag deep into good tissue, not just at the edge of the RTN.

So, perhaps one coral RTN'd in the begining, and now has cause the tank wide event.

Just my 2 cents.

Green skeletons usually indicate phosphates in the water as the coral absorbs it while it builds skeleton (or so I've read). I don't think phosphates are the problem though.

That particular picture is from January or February of last year I believe.

Thank you Ryan for fixing the picture!

Chat, I would frag them if I could, but it just seems to happen so fast that I can't even catch it happening in the process.

Knock on wood, but I think whatever is happening is stabilizing. I haven't had any problems since Friday evening.

Ironically the only corals that have RTNed green like the picture, came from a certain LFS back before I stopped shopping there.