Display refugium as a habitat for invert that isn't reef safe

[Crooked Reef]

Has anyone here ever used an in tank refugium of acclimation box as a permanent habitat for inverts that are not reef safe? My son loves crabs and I was considering adding one that hangs on the side of the tank with some small live rock and allowing one to live in there so he can watch it. Maybe a Pom Pom or emerald or even an arrow crab. We have a porcelain crab in the display that he loves and a couple of emerald crabs in the sump, but the sump is hard to view. I have had issues in a previous tank with emeralds attacking a sleeping wrasse and will not place them in my display anymore. Unfortunately, I don't have the skills that some do to make my cabinet show quality.

My concerns with doing this are as follows. First and foremost, is this space too small? Obviously filtration isn't an issue because it will be in a 90 gallon tank with sump/skimmer. I'm more worried about the mental health of the crab than anything else. Secondly, what are the escape chances? One of my LFS has a wall of small enclosures that house different inverts but this would be a long term thing.

 

[nereefpat]

Someone else here just put a mantis shrimp in his fuge.

http://www.reefcentral.com/forums/showthread.php?t=2669503

What would the tank size be?

 

[Crooked Reef]

Small. I’m looking at an acclimation box size so the footprint is about 7x4 inches. I think it’s probably a bit too tight long term but wanted opinions because I have been way wrong in this hobby before.

 

[ramseynb]

Small. I'm looking at an acclimation box size so the footprint is about 7x4 inches. I think it's probably a bit too tight long term but wanted opinions because I have been way wrong in this hobby before.

I think that would be fine for a small crab. Just put some rock in there to give it some places to roam and hide and keep it fed. I'd look at a strawberry crab. They stay about the size of an emerald but look a lot prettier. They're omnivores like emeralds but eat mostly algae.

 

[homer1475]

I always find it funny how people are so afraid of putting crabs in their tanks. Emeralds especially.

I have always had emeralds in my tanks, as long as they have enough food, they typically stay model citizens. When they run out of food, then they start attacking anything they can(you would too if you got hungry enough). I have yet to have one go rogue, maybe a nibble here, or a nibble there on a coral. Typically they are cleaning algae and happen to nip a coral(I did have one that loved the polyps off my hammer, one or 2 a day never enough to be detrimental to the coral).

I feed mine every other day with a small strip of nori. I don't rely on tank algae to keep them well fed an happy so they don't go rogue like so many horror stories we hear all the time. I like them, think they have a great personality, are great scavengers, and are a perfect addition to a CUC, so I ensure they have an optimal habitat.

IMO an acclimation box is way to small for an emerald. Just dump him in the display, keep him fed, and he'll be a model citizen.

 

[Crooked Reef]

My issue with the emerald was a few years back and came within a day of adding it. Lost a small fish, I don’t remember what exactly. A couple of days later lost another and then a day after that a wrasse has an injury to its side. I saw the crab, caught it and sumped it. No other losses after that. A few months later I tried another thinking I may have just had a rogue show up and lost a firefish within a few days. Removed the crab and no more issues after that. It could all be a coincidence, but I’m not prepared to risk fish to try again. This was a 65 gallon and I am positive they were mithraculus sculptus, first was a male and second a female. My concern was that the box would be too small as well so I’m not going to go for it. I may still get the box and pull him from the sump a few times a week to go into the box for an hour so my son can easily watch him eat mysis for a few minutes.

 

[Crooked Reef]

I have seen the strawberry crab online. There are also red mithrax crabs. Thanks for the suggestion.

 

[sde1500]

Why not keep a pom pom crab in the tank, afaik it is reef safe.

 

[Xxero]

Pom-Pom Crabs are reef safe. But they usually stay hidden unless it's feeding time.

 

[Xxero]

Why not keep a pom pom crab in the tank, afaik it is reef safe.

Beat me to it. :bigeyes:

 

[Uncle99]

After banning all crabs, for more than 17 months now, perhaps it's just luck or coincidence that I have not lost a fish, a coral, or even a snail.

While absolutely correct that as long as they have food they will be good neighbors, I try to keep the feeding to the minimum, just what the fish need, to keep nitrates in the 2-4 ppm range.

If they did a great job in cleanup, I might take the risk but IMO, great water, balanced light in the correct spectrum and low nutrients plus my own to fingers keep it clean

 

[Crooked Reef]

Pom poms stay under an inch. My 5” wrasse kills new crab or shrimp additions. He leaves alone the cleaner shrimp and the porcelain crab, but the porcelain crab is beefy and was there first. I have even seen this wrasse go after new snails and hermits when I drop them in and once killed a peppermint shrimp before it hit the bottom.