Nuisance crab tank (setup questions)

[Fiver]

Call me crazy, but I removed some gorilla crabs (yes, I realize this is a generic term) from my live rock and instead of sending them to the big reef in the sky, I threw them into their own small tank. I'm a sucker.

The tank is bare bottom and all I've done is direct an airstone into the tank from another tank. Can I get away with this and water changes? Or do I need actual filtration? Is a sponge filter even an option?

It has no lights because I do not intend to add any corals. Does it need a light? I do plan to add some live sand and a small live rock.

Thanks.

 

[skp]

Call me crazy, but I removed some gorilla crabs (yes, I realize this is a generic term) from my live rock and instead of sending them to the big reef in the sky, I threw them into their own small tank. I'm a sucker.

The tank is bare bottom and all I've done is direct an airstone into the tank from another tank. Can I get away with this and water changes? Or do I need actual filtration? Is a sponge filter even an option?

It has no lights because I do not intend to add any corals. Does it need a light? I do plan to add some live sand and a small live rock.

Thanks.

I found a small crab, about 1/8th of an inch living in an acro frag and eating the flesh. I took it out and I threw it in an empty tigger pod bottle with just the water that filled a small pipette. I forgot about it and then looked a week later and it was still alive. A lot of the nuisance crabs seem like they can even live through a cycle... comfortably enough that they are eating.

If you want to keep it, just throw your old water in the tank when you do water changes. No need to use new saltwater on it.

 

[Fiver]

I found a small crab, about 1/8th of an inch living in an acro frag and eating the flesh. I took it out and I threw it in an empty tigger pod bottle with just the water that filled a small pipette. I forgot about it and then looked a week later and it was still alive. A lot of the nuisance crabs seem like they can even live through a cycle... comfortably enough that they are eating.

If you want to keep it, just throw your old water in the tank when you do water changes. No need to use new saltwater on it.

That's a good tip; thanks!

 

[Betta132]

All crabs need is food, non-toxic water, and oxygen to survive. They'd probably also prefer to have at least one hiding place per crab. They don't need lights, though tossing a hunk of chaeto in there and lighting it could help provide food/cover.
There's no reason you can't scape it nicely with just rock/shells and have a crab tank. You could even plumb it into your main tank, which would mean that any maintenance done on the main tank would take care of the crabs as well. In that case, they'd just need food.