[spedly]

Last night I noticed a very strange smell near my aquarium. I thought it was coming from a heating vent located near the aquarium so didn't think too much about it. As time wore on the smell became more and more pronounced so I did the sniff test and noticed it was coming from the aquarium. I thought that things looked a little darker but couldn't find the source of the problem. I put my hand in the sump to check something and that's when I noticed it had cooled off significantly. When I pulled my hand out it had a bunch of black muck on it and I noticed bubbles coming from the heater.

Heater blew. Temp was down to about 74 degrees. It's a FOWLR tank right now with some chromis, a pair of clowns, a coral beauty, and a pajama cardinalfish.
Also had a decent CUC consisting of some blue and red legged hermit crabs, astrea snails, some other snails, and three peppermint shrimp.

I was able to get a new heater in there today and it's slowly coming back up to temp. I pulled a couple of dead astrea snails from the tank. The fish seem OK. Probably not very happy with the cold, though. I've seen one live peppermint shrimp but the others are nowhere to be found. The hermit crabs and other snails can't be found right now.

I was unable to do a water change right away because I didn't have any new water mixed (LESSON LEARNED) so that's mixing and heating as we speak and I'm going to do about a 40% water change tomorrow.

The crappy thing is that everything has this light coating of black muck on it. It's very faint. But if I rub my finger across the glass just above the water line it looks like I've painted it with a black marker. It's very black. It's all over the rocks, all over everything. I have no idea what it is. Moreover I have no idea what else could have been in the heater that may hurt the aquarium in the short term. By far my greatest fear is losing the biological filter but so far so good. Still testing 0 for ammonia and 0.25 for nitrite. I think if there was going to be a serious problem there it would have already manifested itself.

I'm curious to know if anyone else has experienced something like this. Especially with the black muck that's all over everything. Any hints on how to clean it up? It's a 55g tank but I have a Tunze 6095 and a 6105 in there (throttled with a 7096 controller). I could turn them on full blast for a few minutes and see if that helps get some of the crap off the rocks. I'd love to hear any suggestions. Thanks.