Refugium Sand Bed help

[thardin]

I am looking for some opinions about how I should deal with my refugium problem.

I had an equipment malfunction (broken heater leaking voltage) a few months ago that caused a fairly serious system crash. I have a 180 gallon main tank with a 100 gallon refugium and a 100 gallon sump. After the crash (during the summer months) I got pretty disgusted with the system and thought I was going to have to start over. I could not find anything wrong with the water parameters, but corals continued to die off. I was very lightyly stocked luckily, so I had only lost about 10-12 specimens. My Squamosa clam, Blue Carpet anemone, bubble coral, frogspawn, and most mushrooms and zoos managed to survive. Many snails and crabs seemed to die-off. Even with all of these things dying off, I had virtually no spikes in Nitrates, Nitrites, Ammonia, etc. I decided to just limp along and begin rebuilding system in the fall.

Well, during the fall months, I began weekly 30 gallon water changes, and increased my maintainence. The main tank is now looking much better. I have now begun to focus my attention on the refugium. I had turned the lights off and stopped growing my macro algae. Now that I am trying to get the fuge back up, I noticed there is virtually no life in there (pods, stars, anything). My sandbed (about 450# at 6" deep) has a fairly hard crust on it and a detrius build-up. I have vacuumed the detrius away, but don't know what else to do. I am afraid that the deep sand bed may have created a time bomb due to lack of maintainence. What happens with a deep sand bed if left alone?

What are my options? I am able to pull the refugium from the system without a problem if it makes sense. Should I rince the sand and start oveer? SHould the sand be discarded? WHat harmful parameters should I test for? I am under the impression that the inactive sand bed has probably caused some Hydrogen Sulfate (or something similar) that might be released if the sand-bed gets stirred-up. ANy thoughts?

[romunov]

I'm not sure you really want a functional DSB in your fuge. They generally don't work out, since the animals in it need to be fed.
See my list of DSB articles. If you have any questions regarding a functional DSB, see Ask Dr. Ron forum. Happy reading.