The whole top lifts off and when you put it back on, there's a gap between the base and the glass top where you can run your wires.
I had freshwater in it, so I just had a powerhead and a sponge filter with a submersible heater.
In the bottom (black part) there's a place for a small light (one...
I've got 3 in my reef tank and they're great. Cute little fish with lots of personality. Mine are out all the time and I love to watch them move around the tank.
My advice, get at least one and have a good time.
Dawn
Mine look like that after I've been messing around in the tank too. One of them comes out right away and the other takes a day or two to come back. Don't worry about it.
I run mine 24/7 also. It doesn't seem to hurt anything and I have some pretty messy eaters, especially in my FOWLR tank. I only change it about once a month, so it's no big hassle and itsn't overly expensive to use.
Yes, in answer to your question, you do need to get them more shells to move into. You can either buy them at your lfs (usually) or order some online.
Every once in a while I'll see a shell I like at my lfs and ask them to give it to me. I've never had anyone tell me no.
I just had a change in lighting and one of mine did the same thing. I found him hiding in the sand, with only his face out to breath. Drove me crazy at first, now, as long as he's still alive, he can do what he wants.
Definately go with the 75 if you can afford to right now. I thought a 30 would be good enough for me for a reef and, of course, now I'm dying to upgrade.
Just keep an eye on them. Mine have had what looked like some scraping from some of the rocks and they've healed just fine without me doing anything.
I hope your day (and your pets) is better than yesterday.
Dawn
I seem to remember someone telling me that Monkey shrimp are not good for a reef tank, but don't remember why. Try doing a search and see what you come up with.
Almost all the stores around here carry them frozen. I also feed mine to all my fish, who will pick them apart and eat the pieces they break off. My eels just eat them whole.