hi, im currently running a 24 gallon nano cube and i have some live rock, live sand, clown fish, dragonet goby, pajama cardinal fish, some red mushrooms, hammerhead coral, and 2 cleaner shrimp. i had one firefish before but it didnt make it past a few days and recently purchased another and it suffered the same fate. what might be wrong. oh yea i also have some sort crab in there which i have seen once or twice since it was in there.