Crab-centric Reef Tank?

[greatbonsai]

I'm finally ready to stock my Fluval Evo sea 5 gallon and I'm thinking of making it an invert reef tank. Fish seem limited in scope and I like an active tank. I have 3 other FW tanks (3, 10, and 35 gal) so I get that the size needs extra work & since it's SW that adds to it - no worries there. 

 

So after reading these and other forums over the last few hours, I'm trying with the idea of making it a crab-centric tank with some corals. I hit the forum search and all I found were species specific threads. 

 

I'd like a good mix (at least 3) of species. I was looking at an emerald, a pompom or 2, and maybe a hermit with many extra shells. Perhaps a docile shrimp (sexy?) species or some cleaner snails to round out the tank. 

 

I know with hermits and snails I'll need extra shells to avoid forced snail eviction/death & with the other crabs I'll need a good amount of feeding to keep them happy & mitigate hunger aggression/coral munching. I have a good amount of live rock (7ish lbs) for climbing/hiding, too. 

 

My main question - is this possible? 

 

If so: 

Do emeralds and pompoms cohabitate well? Will the hermits cause any ruckus with the species I've mentioned? Finally - what corals would be appropriate for the size and stock I'm thinking? Zoas/frogbit/etc?

 

Thanks all! 

[OPtasia]

Any crab or shrimp should only be considered reef safe with caution. I might get a lot of flack for saying that, but my experience with them is that they can't be trusted. I wouldn't add any crabs to your tank without a specific and plentiful food source. Crabs will turn on snails, clams and other inverts if they're hungry. If you really want to add them to a reef tank, work on establishing the tank first. The same with your choice of shrimp, which might one day decide that zoanthus colonies and mushroom polyps are it's favorite dinner option. That's the life of an opportunistic omnivore.

 

 

 

[greatbonsai]

Ok so everything I've read says to get a cuc in there first (hermits and/or snails), but now you're saying to get the tank 'established' first? 

 

So... Corals first, then hermits and snails, then other crabs (one at a time)? Or... What? 

 

As for the food source - yes I figured that. Is feeding the tank once/twice a day not enough? I'm not thinking about any fish, so any food source would be dedicated to the crabs/other inverts. 

[jesseatam]

By established they probably mean cycled with some algae growth so there's a good source for the CUC. Another cool crab you should into are porcelain crabs, there are two varieties and one can be hosted by anemones too which could make for an interesting display.

[Thunder Goose]

I'm an exception in liking crabs. I have emeralds in my 55 that are well behaved (but I do feed Nori regularly) and a bunch of small hitchhiking crabs in my nano (the only one I've been able to ID is an acropia crab and I don't have any acropia). I also keep mini hermits (the blue legs) which are reasonably well behaved. I had to sump a dwarf zebra hermit because he went on a murder spree. I still like him.

 

BUT, except for the hermits, they tend to hide. If you want a lot of activity go with small shrimp, like the sexy or Pederson's or spotted anemone shrimp or similar sized ones that show up from time to time (try KP Aquatics for the three I mentioned).

 

Sounds like a fun project!

[JoeR]

BL Hermit crabs are the biggest jerks. They rip food straight out of my coral’s mouth, especially acans. I provided them with plenty of shells and they still decided to murder my snails too. But I still like them, they’re interesting. I have one that hasent grown since I bought him and another one that’s HUGE probably in a 2” shell.

 

Sexy shrimp are awesome! Love them. Highly recommend. Mine walk on zoas and irritate them but that’s about it, no problems with them eating coral I don’t think.

 

Pom Pom are probably the coolest but once you put them in the tank that’s about all you’re gonna see of them. They hide 24/7 in my tank. 

 

I had a white porcelain which was super cool, especially the way he fanned the water, but he didn’t last long. Not sure why. Think he may have starved

 

I have no experience with emeralds but otherwise I’d think the tank would work. Might be too much of a bioload  though if you get all of them, but since it’s a 5 gallon it’s easy to just do a few WC.

 

I have found the smaller the tank is the easier it is to maintain. Others will tell you otherwise but don’t listen to them unless they have both Picos and large systems.

[RayWhisperer]

Crabs are what they are. As long as you understand the risks involved, I see no problem with doing a tank focused on them. Hermits will kill a few snails, regardless of how many empty shells you give them. Pom poms will hide a lot. Porcelain crabs won’t move much. Sexy shrimp will probably nibble at corals. Peppermints will possibly eat zoas. Banded corals will probably eat any small shrimp. Mantis shrimp will eat them all. As long as you understand this, you’ll get exactly what you’d expect to get. 

 

FWIW, I’ve had hermits in every tank I’ve ever set up. They make fantastic scavengers and algae eaters, even if it costs me a few snails.

[Lula_Mae]

On 1/1/2018 at 11:40 PM, greatbonsai said:

I'm finally ready to stock my Fluval Evo sea 5 gallon and I'm thinking of making it an invert reef tank. Fish seem limited in scope and I like an active tank. I have 3 other FW tanks (3, 10, and 35 gal) so I get that the size needs extra work & since it's SW that adds to it - no worries there. 

 

So after reading these and other forums over the last few hours, I'm trying with the idea of making it a crab-centric tank with some corals. I hit the forum search and all I found were species specific threads. 

 

I'd like a good mix (at least 3) of species. I was looking at an emerald, a pompom or 2, and maybe a hermit with many extra shells. Perhaps a docile shrimp (sexy?) species or some cleaner snails to round out the tank. 

 

I know with hermits and snails I'll need extra shells to avoid forced snail eviction/death & with the other crabs I'll need a good amount of feeding to keep them happy & mitigate hunger aggression/coral munching. I have a good amount of live rock (7ish lbs) for climbing/hiding, too. 

 

My main question - is this possible? 

 

If so: 

Do emeralds and pompoms cohabitate well? Will the hermits cause any ruckus with the species I've mentioned? Finally - what corals would be appropriate for the size and stock I'm thinking? Zoas/frogbit/etc?

 

Thanks all! 

I would suggest a pom pom crab or two (they tend to be reclusive but each is different), porcelain crabs (there are several varieties, my favorite are the green Caribbean ones but other varieties are beautiful too), and Pederson's or similar anemone shrimp.  Emerald crabs and sexy shrimp have both been known to eat corals if they decide they want them (even if fed).  If you do a hermit, try a scarlet as they are supposed to be the most docile.  I finally got one (after two empty shells from LiveAquaria lol) and so far so good as he trundles around my jar.

 

If you do decide to try a fish, I suggest a green banded goby or bimaculatus blenny. 

 

13 hours ago, Thunder Goose said:

I'm an exception in liking crabs. I have emeralds in my 55 that are well behaved (but I do feed Nori regularly) and a bunch of small hitchhiking crabs in my nano (the only one I've been able to ID is an acropia crab and I don't have any acropia). I also keep mini hermits (the blue legs) which are reasonably well behaved. I had to sump a dwarf zebra hermit because he went on a murder spree. I still like him.

 

BUT, except for the hermits, they tend to hide. If you want a lot of activity go with small shrimp, like the sexy or Pederson's or spotted anemone shrimp or similar sized ones that show up from time to time (try KP Aquatics for the three I mentioned).

 

Sounds like a fun project!

My zebra hermit was a terrible reef citizen.  Never again!

 

13 hours ago, JoeR said:

BL Hermit crabs are the biggest jerks. They rip food straight out of my coral’s mouth, especially acans. I provided them with plenty of shells and they still decided to murder my snails too. But I still like them, they’re interesting. I have one that hasent grown since I bought him and another one that’s HUGE probably in a 2” shell.

 

Sexy shrimp are awesome! Love them. Highly recommend. Mine walk on zoas and irritate them but that’s about it, no problems with them eating coral I don’t think.

 

Pom Pom are probably the coolest but once you put them in the tank that’s about all you’re gonna see of them. They hide 24/7 in my tank. 

 

I had a white porcelain which was super cool, especially the way he fanned the water, but he didn’t last long. Not sure why. Think he may have starved

 

I have no experience with emeralds but otherwise I’d think the tank would work. Might be too much of a bioload  though if you get all of them, but since it’s a 5 gallon it’s easy to just do a few WC.

 

I have found the smaller the tank is the easier it is to maintain. Others will tell you otherwise but don’t listen to them unless they have both Picos and large systems.

Pom poms are usually reclusive but each has their own personality; my Shelby was very bold.  And tried to eat her fellow pom pom, so there's that.  My two current poms get along famously and are more bold together than one was by itself.

[greatbonsai]

Thanks everyone! 

 

So I ended up going out and getting 2 hermits and 2 margarita snails as the shop was out of turbos. Of course *then* I read that the margaritas aren't truly tropical... My tank stays at about 78* though so we'll see what happens. Also saw 2 stomatella snails last night! Must have been hiding in the live rock these past few months (the tank has been 'cycling' for about 3 months). 

 

So I'll see how these few residents go - though the stomatella snails and pods I'm seeing give me hope that the tank is nice and healthy. My SG is a little low - 1.020 - so with the next couple of water changes I'll raise it ever so slightly each time. Once I'm confident the tank isn't going to bomb on me, I'll add in a couple small frags from my lfs - looked like zoas are my best bet last time I was in. I know a pompom crab is coming in the near future as well, possibly some sexy shrimp. What other corals would the community suggest? 

[Cannedfish]

23 hours ago, JoeR said:

 But I still like them, they’re interesting. I have one that hasent grown since I bought him and another one that’s HUGE probably in a 2” shell.

Weird I have had the same thing happen. One is tiny, the other is a monster. 

 

14 hours ago, RayWhisperer said:

 Porcelain crabs won’t move much. Sexy shrimp will probably nibble at corals. Peppermints will possibly eat zoas. Banded corals will probably eat any small shrimp. Mantis shrimp will eat them all.

Succinct and hilarious. My Sexy's are the biggest pain in my ass, if I don't target feed them at least once (sometimes twice a day) they wander off to pick at whatever they feel will piss me off the most, currently they have had a taste for my Jedi Mind Trick Monti. Would a five gallon be enough for a tail spot blenny? I feel that would be more entertaining than everything mentioned, except maybe the mantis. 

[BustytheSnowMaam]

I have a Daum's reef lobster that has lived in my tank for about 10 years.  They're secretive yet neat inhabitants, they don't bother anything, and they live forever.  Would recommend.  

[Lula_Mae]

4 hours ago, Cannedfish said:

Weird I have had the same thing happen. One is tiny, the other is a monster. 

 

Succinct and hilarious. My Sexy's are the biggest pain in my ass, if I don't target feed them at least once (sometimes twice a day) they wander off to pick at whatever they feel will piss me off the most, currently they have had a taste for my Jedi Mind Trick Monti. Would a five gallon be enough for a tail spot blenny? I feel that would be more entertaining than everything mentioned, except maybe the mantis. 

I think 5 g should be fine for a TSB, it's often recommended for that size tank.

 

3 hours ago, tashayar said:

I have a Daum's reef lobster that has lived in my tank for about 10 years.  They're secretive yet neat inhabitants, they don't bother anything, and they live forever.  Would recommend.  

How big is yours? Are they truly reef-safe? I see them on LiveAquaria a lot and have been curious about them.

[BustytheSnowMaam]

1 minute ago, Lula_Mae said:

 

 

How big is yours? Are they truly reef-safe? I see them on LiveAquaria a lot and have been curious about them.

Mine is roughly 4" long and doesn't bother anything.  He comes out for his bi-weekly piece of fish and then retreats to his cave.  He and my dwarf angel sometimes sleep in the same cave at night.  I have a pic, if I can find it I'll post it.  He's not super-charismatic or anything, but I'd rather have a critter that lives forever than a cleaner shrimp, because they only live a year or so.  

[BustytheSnowMaam]

Here's the pic (sorry it's not the best) of my lobster and dwarf angel sharing a cave.  They're best buddies.  

[Dos Ocho]

I have a 10 gallon that is all hermits, no fish. 7 blue leg hermits. They were disruptive jerks in a bigger tank but were one of the first critters I bought so I couldn’t part with them. I also have 2 cerith snails and an Astrea. The ceriths stay buried in the sand most of the time and the Astrea cruises the glass, so the crabs don’t have much of a chance to bother them. I have a few corals and macroalgae for filtration and looks.

i feed the hermits small chunks of sinking algae pellets and recently shavings of a piece of cod that never made it to the dinner table. Small daily feedings and no more food until I verify the last meal is totally gone. Plenty of empty shells too.

so far, it is working well. I have Xenia and GSP that they don’t bother. I have a couple Blastos that can be transferred to my other tank if the little guys start attacking them.

they do fight a lot amongst themselves and one got much bigger than the others and he is the king bully. Sometimes he’ll pin another crab to the sand and pick at him for hours, even days but no murders so far.

i’ve found that the small feedings don’t contribute much bioload. In fact, i just have an empty HOB filter that provides circulation and rely on trimming a clump of caulerpa and 2 gallon weekly water changes for nutrient export. Not a visually pretty tank by any means, but it is fun to watch the little guys scurry around.

just my fishless reef tank observation! Good luck to you.