Flashlight fish are pretty new to the home aquarium industry. You're going to have a tough time finding information about them. I think they are fairly hard to keep alive. I'd guess they are nocturnal in nature, so a low light aquarium would probably suit them best.
ya after reading some on them, id do a low light tank with a lot of caves and such for them to hide. they are nocturnal so you will have to keep that in account. there is some info on the net so id read as much about them as possible before designing the tank or buying one.
Good luck with him...
I had 2 of them..
One lasted 1 night and the other 3 nights..
They need little to no light. You will not see them all day losg and they only come out at night for food. They were very cool. I would not suggest getting them. My water levels were perfect too. They just didn't eat, couldnt' find anything. They didn't come out till all the lights were off. I even had to kill my moon lights for them to come out.