Dead Sea Urchin in Tank - Help!
 

I'm trying to maintain the best water quality I can in two tanks that are holding my livestock until the large tank is set up and running over the weekend. Nitrites are measuring .1 in both tanks. I have been doing small water changes each evening. Tonight when I got home the sea urchin was dead and most of the spines had fallen off the body. I have removed it and did a 10% water change. Will urchins release any deadly toxins? The corals are not looking that great but the lights were out all day. Anything else I should be doing immediately other than water changes?

Wouldn't be worrying about the urchin releasing anything, but with nitrites might be wanting to do more than just little water changes.

You could dose with some "seachem stability" It will help with the nitrites.