Volta has some tankmates in with him. I put 20 feeders in there about two years ago and there was only 6 left as of 2months ago. I took them out though. They were getting way to big. I just put some catfish in there last week. Hes to slow to catch them. Plus i keep dubia roaches in there for him to eat. Its freshwater i put a little salt in there . 1Tbs per 5 gallons whenever i rearrange tank. When i got him he was 2inches across and with legs about 5inches across. Now hes about 4 inches across and with legs hes about 10-12 inches leg to leg. He's very aggressive! But yes fun and interesting. If I ever have to do maintence inside I make sure where he is before sticking my hand in there. Ive gotten zapped too because he chews on the power chord sometimes. Ive gone through 3 filters in the time of owning him. Did your fiddlers ever molt? Orbdidnt they make it that long. Its such a trip seeing their exoskeleton just sitting there. Then they eat it. pretty gnarly.Used to have several fiddler crabs with some mollies in a 20g long, but they kept escaping, so had to rehome them. Crabs are cool though. Do you have any fish with yours, or would fish just be eaten? Is it a brackish, fresh, or salt water crab? How large is it?
Sorry for all the questions, but I'm always interested in animals I don't, or can't have.