Setting Up an Arrowcrab Tank?

WeightedAbyss75

Arachnoangel
Joined
Feb 22, 2014
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921
Hola! Not sure if anyone on this forum can really answer this, but I figured crabs are inverts too :D I recently saw an arrowcrab at my LPS and love them to death. I have been increasing interested in underwater inverts as well as land dwellers, so I'd love to own some. Only problem is that they are saltwater. My only experience with an aquarium is with a 30 Gal when I was little that my parents mostly kept. Had to sell it. I worry about the upkeep with water changes, equipment, etc. to buy for only 1 crab. I know how aggresive they can be, so I would probably just keep it by itself or with other inverts or clean up crew that it can't kill. Is there an easy way to set a tank like that up, or is it not worth the money? If you have any other info, like size of aquarium or food for one, then that would be great too. Just super interested in the many crab species avalible, especially arrow crabs.

Thanks for reading, Abyss
 

Stugy

Arachnolord
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Apr 21, 2016
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648
IMO It is way more worth the time and stress to have a saltwater aquarium with different kinds of animals rather than one species. Especially for just one crab lol.
 

WeightedAbyss75

Arachnoangel
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Feb 22, 2014
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921
IMO It is way more worth the time and stress to have a saltwater aquarium with different kinds of animals rather than one species. Especially for just one crab lol.
True, just hear they like to kill other fish most of the time. Figured it would be better off alone than with other smi-expenive fish or other inverts :D Never even heard what CAN be in with an arrow crab...
 

Arachnomaniac19

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Joined
Aug 23, 2014
Messages
654
Make sure you get a power head or two, some porous live rock (or a bit of live with some dry rock), and good lights if you want some corals. Obviously get a large tank since they get rather big. Make sure to top off the water since salt doesn't evaporate (although salt creep is annoying!). Also, remember to dechlorinate and keep your heavy metals down! Stuff like copper is pretty toxic to these types of arthropods.
 

WeightedAbyss75

Arachnoangel
Joined
Feb 22, 2014
Messages
921
Make sure you get a power head or two, some porous live rock (or a bit of live with some dry rock), and good lights if you want some corals. Obviously get a large tank since they get rather big. Make sure to top off the water since salt doesn't evaporate (although salt creep is annoying!). Also, remember to dechlorinate and keep your heavy metals down! Stuff like copper is pretty toxic to these types of arthropods.
How often should I do water changes? And yes, I am a complete noob. Guessing it's based on how many animals are in the tank, amount of food, waste, etc.? Also, would I need the "full setup"? Figure a smaller tank with a select few small inverts and a crab wouldn't be too much effort compared to a tank with many different types of fish. Just figuring though, in my LPS they are small (around the 2-3" mark). Thought a 15 Gal would work with some natural rock for filtration :D
 

Arachnomaniac19

Arachnolord
Joined
Aug 23, 2014
Messages
654
How often should I do water changes? And yes, I am a complete noob. Guessing it's based on how many animals are in the tank, amount of food, waste, etc.? Also, would I need the "full setup"? Figure a smaller tank with a select few small inverts and a crab wouldn't be too much effort compared to a tank with many different types of fish. Just figuring though, in my LPS they are small (around the 2-3" mark). Thought a 15 Gal would work with some natural rock for filtration :D
It really depends on the bioload. With some small inverts maybe once every two weeks to a month. A 15gal will work, just be careful about the water parameters. My first SW was a 10gal, and that was pretty easy. Make sure to get live rock to seed the tank with beneficial bacteria. The freshwater species obviously won't live long in saltwater.
 

WeightedAbyss75

Arachnoangel
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Feb 22, 2014
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921
I hear you also have to let it sit to cycle first right? Do a water change or two and then see how it does with the live rock? One more thing about water changes, what is the best way to do them? Pump, cup, or what? I have read you take about a fourth and replace it with new salt water? Or only fresh water once the salt is in the water?
 

Arachnomaniac19

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Aug 23, 2014
Messages
654
I hear you also have to let it sit to cycle first right? Do a water change or two and then see how it does with the live rock? One more thing about water changes, what is the best way to do them? Pump, cup, or what? I have read you take about a fourth and replace it with new salt water? Or only fresh water once the salt is in the water?
You have to let the rock cycle first. If you Google live rock cycling you'll get a better idea. I siphon my water out wirh a gravel vacuum. I usually take out 20% or so. You have to replace it with saltwater or else you tank will eventually turn into a freshwater tank. Replace the evaporated water with freshwater though.
 

WeightedAbyss75

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Feb 22, 2014
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Just to make sure I get this right, what Ph should I keep the water at? Is it different for inverts than fish, or not?
 

Arachnomaniac19

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Aug 23, 2014
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Just to make sure I get this right, what Ph should I keep the water at? Is it different for inverts than fish, or not?
I don't bother with pH. If you have snails, keep the clacium levels up and the pH over 7, but other than that don't stress about it. Trying to change it will cause more damage than good. If you need to make it go higher you can use crushed corals as part of your substrate.
 

sschind

Arachnobaron
Old Timer
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May 27, 2005
Messages
344
One of the coolest saltwater tanks I ever was was a 10 gallon hexagon tank with live rock and some live caulerpa but the central attraction was a single Arrow crab. The live rock was arranged so that right in the center of the tank there was sort of a sheltered grotto looking cave and the crab set up house right in the middle of it. You could do something similar and very easily especially if you didn't care about the macro algae. If you are not trying to keep corals or anemones you won't need special lighting or filtration. If the arrow crab was going to be your only resident you could get by with a 10 gallon tank (they don't get that big) but if it were me I'd go with a taller tank (that's why the hex looked so cool) You mentioned a 15 gallon but I'd go with an Aqueon 20 extra high (same footprint as a 10 gallon but twice as tall because the height makes for a nice pile of live rock. Speaking of live rock it will most likely be the most expensive part of your setup. IMO you will want to pretty much fill the tank so 20-30 pounds would not be unreasonable. Of course you do not have to add it all at once and you don't NEED that much but like I said, that's what I would want. You could save some money by buying a bunch of cheaper base rock and filling it in with better cured live rock which will eventually colonize the rest of your rock. Of course with an arrow crab there won't be much in the way if inverts to colonize. Its possible a fast moving fish or two like damsels or better yet green chromis would be OK with the crab but I wouldn't plan on spending too much on anything fancy.

People get scared of saltwater because they think they need such specialized equipment but I have kept SW fish very successfully in tanks with the exact same equipment as I would use for freshwater. Especially with the new LED lighting that is available. The only difference is the substrate (use crushed coral or aragonite) the live rock and the salt. It all depends on what your goals are. You want corals and anemones? Yeah, its gonna be a bit more tricky but you can keep some very beautiful saltwater tanks with no more difficulty than a fresh water tank if you know the limits.

I can't say whether or not it's worth it to keep a single crab because obviously that is up to you but arrow crabs are one of my favorites and I wouldn't have a problem with spending the money if it wasn't needed elsewhere.
 

Arachnomaniac19

Arachnolord
Joined
Aug 23, 2014
Messages
654
One of the coolest saltwater tanks I ever was was a 10 gallon hexagon tank with live rock and some live caulerpa but the central attraction was a single Arrow crab. The live rock was arranged so that right in the center of the tank there was sort of a sheltered grotto looking cave and the crab set up house right in the middle of it. You could do something similar and very easily especially if you didn't care about the macro algae. If you are not trying to keep corals or anemones you won't need special lighting or filtration. If the arrow crab was going to be your only resident you could get by with a 10 gallon tank (they don't get that big) but if it were me I'd go with a taller tank (that's why the hex looked so cool) You mentioned a 15 gallon but I'd go with an Aqueon 20 extra high (same footprint as a 10 gallon but twice as tall because the height makes for a nice pile of live rock. Speaking of live rock it will most likely be the most expensive part of your setup. IMO you will want to pretty much fill the tank so 20-30 pounds would not be unreasonable. Of course you do not have to add it all at once and you don't NEED that much but like I said, that's what I would want. You could save some money by buying a bunch of cheaper base rock and filling it in with better cured live rock which will eventually colonize the rest of your rock. Of course with an arrow crab there won't be much in the way if inverts to colonize. Its possible a fast moving fish or two like damsels or better yet green chromis would be OK with the crab but I wouldn't plan on spending too much on anything fancy.

People get scared of saltwater because they think they need such specialized equipment but I have kept SW fish very successfully in tanks with the exact same equipment as I would use for freshwater. Especially with the new LED lighting that is available. The only difference is the substrate (use crushed coral or aragonite) the live rock and the salt. It all depends on what your goals are. You want corals and anemones? Yeah, its gonna be a bit more tricky but you can keep some very beautiful saltwater tanks with no more difficulty than a fresh water tank if you know the limits.

I can't say whether or not it's worth it to keep a single crab because obviously that is up to you but arrow crabs are one of my favorites and I wouldn't have a problem with spending the money if it wasn't needed elsewhere.
I really wouldn't recommend keeping anenomes in such a small tank. They get way too big IMHO! I also think the X lbs of rock per X gallons rule is trash. The bacteria doesn't care about how heavy it is, they care about how much room they have! If you have extremely porous rocks, you could get by with hardly any weight. That's not to say it's not a good starting point, but that's the same as the X" of fish per gallon rule that everyone knows is completely false. It might work with some, but it could also fail horribly.
 

WeightedAbyss75

Arachnoangel
Joined
Feb 22, 2014
Messages
921
One of the coolest saltwater tanks I ever was was a 10 gallon hexagon tank with live rock and some live caulerpa but the central attraction was a single Arrow crab. The live rock was arranged so that right in the center of the tank there was sort of a sheltered grotto looking cave and the crab set up house right in the middle of it. You could do something similar and very easily especially if you didn't care about the macro algae. If you are not trying to keep corals or anemones you won't need special lighting or filtration. If the arrow crab was going to be your only resident you could get by with a 10 gallon tank (they don't get that big) but if it were me I'd go with a taller tank (that's why the hex looked so cool) You mentioned a 15 gallon but I'd go with an Aqueon 20 extra high (same footprint as a 10 gallon but twice as tall because the height makes for a nice pile of live rock. Speaking of live rock it will most likely be the most expensive part of your setup. IMO you will want to pretty much fill the tank so 20-30 pounds would not be unreasonable. Of course you do not have to add it all at once and you don't NEED that much but like I said, that's what I would want. You could save some money by buying a bunch of cheaper base rock and filling it in with better cured live rock which will eventually colonize the rest of your rock. Of course with an arrow crab there won't be much in the way if inverts to colonize. Its possible a fast moving fish or two like damsels or better yet green chromis would be OK with the crab but I wouldn't plan on spending too much on anything fancy.

People get scared of saltwater because they think they need such specialized equipment but I have kept SW fish very successfully in tanks with the exact same equipment as I would use for freshwater. Especially with the new LED lighting that is available. The only difference is the substrate (use crushed coral or aragonite) the live rock and the salt. It all depends on what your goals are. You want corals and anemones? Yeah, its gonna be a bit more tricky but you can keep some very beautiful saltwater tanks with no more difficulty than a fresh water tank if you know the limits.

I can't say whether or not it's worth it to keep a single crab because obviously that is up to you but arrow crabs are one of my favorites and I wouldn't have a problem with spending the money if it wasn't needed elsewhere.
What kind of equiment did you use in the aquarium? I know of powerheads that create current, but how muchncurrent do I need and where? Thanks for the reply, do you have any pics? Glad someone else has tried that type of setup, what did you feed it and how often? Sounds like a great looking tank :D
 

KevinsWither

Arachnolord
Joined
Jul 11, 2014
Messages
643
Now I kept freshwater fish and its really easy. Saltwater, they are kind of delicate (orchid mantis delicate). As long as you keep up with the parameters well and know what your doing, you can have a nice saltwater invert tank with a fish or two, arrow crab, a cleaner crew composed of snails, hermit crabs and a small sea star, some easy corals, and a few shrimp.
 

Nephila Edulis

Arachnoknight
Joined
Feb 27, 2017
Messages
201
On topic: Definitely get an arrow crab in a 10 gal it's well worth it. Just make sure there's no unwanted visitors who might eat your crab. Saltwater can be demanding but it's worth it. From my experience most of the carnivorous crustaceans won't attack sea cucumbers (they probably taste like rubber). The cucumbers make a good clean up crew for sand.

Off topic: My experience with a saltwater tank was getting a good sized tank and spending quite a lot of money on live rock. I let the tank sit without any fish from te pet store for a bit with just the live rock and some small saltwater fish I caught down at the Phillip island pier (don't worry those fish are everywhere and don't have a bag limit or size limit, I was getting some carnivorous fish too so they would act sort of like feeder crickets). Well I never ended up with some colourful fish but I did find a little mantis shrimp in the live rock. Had that shrimp for a year and he never broke the glass like they have a reputation for doing. He did eat the little fish though. I'd say that you should definitely get an arrow crab and place some feeder fish in the tank. Watching crustaceans hunt reminds me of watching my Ts hunt and it's very entertaining
 

Nephila Edulis

Arachnoknight
Joined
Feb 27, 2017
Messages
201
On topic: Definitely get an arrow crab in a 10 gal it's well worth it. Just make sure there's no unwanted visitors who might eat your crab. Saltwater can be demanding but it's worth it. From my experience most of the carnivorous crustaceans won't attack sea cucumbers (they probably taste like rubber). The cucumbers make a good clean up crew for sand.

Off topic: My experience with a saltwater tank was getting a good sized tank and spending quite a lot of money on live rock. I let the tank sit without any fish from te pet store for a bit with just the live rock and some small saltwater fish I caught down at the Phillip island pier (don't worry those fish are everywhere and don't have a bag limit or size limit, I was getting some carnivorous fish too so they would act sort of like feeder crickets). Well I never ended up with some colourful fish but I did find a little mantis shrimp in the live rock. Had that shrimp for a year and he never broke the glass like they have a reputation for doing. He did eat the little fish though. I'd say that you should definitely get an arrow crab and place some feeder fish in the tank. Watching crustaceans hunt reminds me of watching my Ts hunt and it's very entertaining
Also be careful that your crab doesn't die on you. Aquarium fish breeders put antibiotics in their tanks and often you'll lose a fish because it won't be used to the conditions of the new tank. this happened to a lion fish a friend of mine had
 

WeightedAbyss75

Arachnoangel
Joined
Feb 22, 2014
Messages
921
On topic: Definitely get an arrow crab in a 10 gal it's well worth it. Just make sure there's no unwanted visitors who might eat your crab. Saltwater can be demanding but it's worth it. From my experience most of the carnivorous crustaceans won't attack sea cucumbers (they probably taste like rubber). The cucumbers make a good clean up crew for sand.

Off topic: My experience with a saltwater tank was getting a good sized tank and spending quite a lot of money on live rock. I let the tank sit without any fish from te pet store for a bit with just the live rock and some small saltwater fish I caught down at the Phillip island pier (don't worry those fish are everywhere and don't have a bag limit or size limit, I was getting some carnivorous fish too so they would act sort of like feeder crickets). Well I never ended up with some colourful fish but I did find a little mantis shrimp in the live rock. Had that shrimp for a year and he never broke the glass like they have a reputation for doing. He did eat the little fish though. I'd say that you should definitely get an arrow crab and place some feeder fish in the tank. Watching crustaceans hunt reminds me of watching my Ts hunt and it's very entertaining
Thanks for the info! Just a question, I hear that sea cucumbers don't respond well to changes in water parameters. I have heard that many can be stressed and die from decent flucuations. Also, they can blow up like a balloon and/or explode and destroy everything in the tank with poison. At least, that's what I read. Will need to be super prepared though. Saltwater seems super interesting, but I probably am going to wait until the Summer when I have extra time :D Would love to have big invert tanks kept like my T's. Figure it could be cool to keep many cool inverts within small saltwater aquariums ;)
 

Nephila Edulis

Arachnoknight
Joined
Feb 27, 2017
Messages
201
Thanks for the info! Just a question, I hear that sea cucumbers don't respond well to changes in water parameters. I have heard that many can be stressed and die from decent flucuations. Also, they can blow up like a balloon and/or explode and destroy everything in the tank with poison. At least, that's what I read. Will need to be super prepared though. Saltwater seems super interesting, but I probably am going to wait until the Summer when I have extra time :D Would love to have big invert tanks kept like my T's. Figure it could be cool to keep many cool inverts within small saltwater aquariums ;)
Never heard of exploding sea cucumbers, but they definitely throw their guts out to scare away predators. I kept one for a year and it never exploded despite water quality changing a lot. Might differ with different kinds. Best of luck
 
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