HCA: Hermit Crab Association

Hi there! I'm new here & new to hermit crabs (I don't even own any hermit crabs yet, but I plan on getting some relatively soon). I just have some questions about setting up a "crabitat.."

First off, the tank size I'm getting will be 10 gallons.

•What should I do to heat the tank?!
I've read some about lighting/heating, & to be honest, it kind of confused me. D: Should/can I leave the heat source on 24/7? Should I just have an under tank heater? I read somewhere that a UTH can overheat because of the substrate though.. If I do a light, do I use a night lightbulb and still use that bulb during the day or what? ahhh I need help..

•Should I use sand, Eco-earth, or both? How often do I need to replace it?
Just want a few opinions on which would be the easiest to keep clean.

•How many shells do I need in the tank with 3 crabs?
I'll probably get 3 crabs, and I'd like to know how many empty shells I need to keep in the tank for them. (3 crabs will be comfortable in a 10 gallon tank, right?)

•Can I feed them a commercial crab food? What kind?
I've read that most commercial crab foods are bad for them because of pesticides and such, but is there any brand that is safe for them to eat as the staple of their diet? I'd just rather not have to make the food for them myself..

•How often should I replace their water?
Just wondering. Also, how much aquarium salt do I need to mix into the water for the saltwater dish?


I apologize for having so many questions! It's just that I'd like to get it right the first time rather than go through too much trial and error. Any advice is greatly appreciated!

Hello,
-Most members use UTHs for heating, they are usually cheaper in the long run than a lamp. The best brand is Ultratherm. They are only sold online but are great quality. You should buy one that fits on the back of the tank from top to where the substrate starts.
-Play sand alone doesn't need to be replaced as far as I know (someone correct me if I'm wrong) only food pieces that get dragged out of the food dish need to be cleaned up.
Those who use eco earth usually replace it every 6 months I believe. I think it has something to do with bacteria growth.
-3 in a 10 gallon is fine if they are really small. However they will grow out of a 10g quickly A good number would probably be 5-6 shells per crab .
-There are only a few commercial foods that are safe. It's all listed here hermitcrabassociation.com/phpBB/viewtopic.php?f=25&t=92555
-Water changes are suppose to be done every few days to keep anything from growing in the water.
Look on the box of the salt mix to figure out how much to put in the water.
Hope this helps

Heat doesn't have to be steady, but it should be at least 80 during the day and no lower than 75 at night. Depending on how your tank reacts and how warm your home is, that may mean having a heat source on constantly. It's a good bet you'll need 24 hour heating for most of the year if you're in a cooler climate. UTH should never be used underneath a tank - only on the back or side. And yes, a single good quality (Ultratherm) that is the size of the back of your tank should be enough to get you to where you need to be without having to mess around with heat bulbs. If you wanted to go with bulbs, any night reptile bulbs can be left on 24 hours a day. White light - the kind we use for our homes - can only be used during the day or it screws with their internal clocks. Fluorescent lighting (the long tubes for fish, or the swirly bulbs we use in our homes) puts out white light and next to no heat if you wanted to light the tank to watch them during the day.

Most people recommend a mix of mostly silica based playsand and a little cocofiber because it offers the best tunneling and holds moisture well. Substrate never has to be changed unless it floods. We have people who haven't changed their substrate in a decade! I haven't replaced mine since building my big tank four years ago, I just scoop off the top layers as they get it messy and replace it with fresh as the level drops.

If the crabs are all the same size you won't need as many extra shells. Each crab should have roughly 3 to 4 shells around the size it should be wearing. Double that number for when you have multiple crabs that are wearing the same size. The idea is to give them enough choices where they won't be fighting over the same one, but you don't have to go crazy unless you wanted to. Make sure the shell species is the right kind for the species of crab you have. Having the wrong shells only wastes space and doesn't help them!

Teeny tiny crabs work well in 10 gallons and may be comfortable there for two to five years before they get too large. And by teeny, I mean a crab that with it's shell will fit on a dime. They can grow startlingly fast, and overcrowding can lead to death. If you aren't planning on upgrading anytime in the near future, you want the smallest ones you can get.

The commercial food link isn't working for me, so I'll repost it here: http://hermitcrabassociation.com/phpBB/ ... 25&t=92555

Daily water replacement is best if you can.

All of the major salt brands are measured the same, depending on how much you need:

1 gallon of water to ½ cup of salt mix
½ gallon (which is 2 quarts) of water to ¼ cup salt mix
1 Pint (which is 2 cups) of water to 1 Tablespoon (which is 3 teaspoons) salt mix
1 cup of water to ½ Tablespoon (which is 1 and ½ teaspoon) of salt mix

Check out our index of articles here: http://hermitcrabassociation.com/pages/

And since this thing took forever to make and I like spamming it everywhere, an idea of what a 10 gallon tank should look like:

Thank you so much for all of that info!

So, a 10 gallon is a bit small, then? I'd rather them not grow out of the tank too quickly; I want them to be comfy for awhile! What would be a better size to start with?

If your crabs are pretty small, I think a 10 should last you a good while. However, many of us are so addicted we upgrade sooner than we have to - I went from a 15 to a 29 to a 55 in less than 2 months.

If you're wanting to start out with a bigger one, though, I personally think a 29 is a good size. If you have a Petco in your area, they're have a $1/gallon sale. Craigslist is also a good place to check for deals.

Ah, okay! I might start w/ a 15 instead; I don't think I'd have space for a 29, lol.

Oh btw, if I use a UTH on the back of the tank (which I probably will...sounds easier than using bulbs), do I leave that on 24/7?

15 is good, too! It just gives you that much more space for decorating

Most of us leave ours on 24/7. Personally, even with the big one I have on my 55 gallon, I still have to supplement with heat bulbs but it all depends on your house.

15 gallons are a weird size and are somewhat hard to find. A 15 gallon standard is the same footprint but is much shorter than a 20 gallon tall. A 15 gallon extra tall (which is what I upgraded the 10 in the photo to last week) is the same footprint as a 10 gallon but with 6 extra inches on top.

So if it has the same footprint, why upgrade? More climbing space?

Btw thanks for all of your help guys!

Exactly that! The kitchen counter I have the tank on could only take something that was 11 inches or skinnier. Anything larger would have been 12 inches wide. I got the tank with an adoption and I've been dying to use it somehow and it fits the space perfectly. Since the tank is taller now and the crabs are all really tiny, it's 1/3 substrate and 2/3 climbing space which I think looks better than the old one that was 50/50.

hermitcrabdc wrote: -Water changes are suppose to be done every few days to keep anything from growing in the water.
Look on the box of the salt mix to figure out how much to put in the water.

I use distilled water that I buy in gallon jugs at the store. Others in the forum have been using dechlor products. I using the wrong kind of water for drinking and for mixing saltwater?

Apparently, the process used to distill water doesn't necessarily take everything out of the water. Which to me means they shouldn't be able to call it distilled water, because by definition it's supposed to be pure.

What most folks find to be a better option is using a really good dechlorinater like Seachem Prime in regular tap water. It will neutralize all the bad stuff, and in the long run will be much cheaper than buying distilled water.

^yep

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Thank you for this advice! I thought distilled really meant pure because that's how the chemistry works! Now I'm wondering what is in the same water that I use in my netipot for sinus rinses, ack!

Distilled does not mean sterilized! There was just a case a few years ago of people getting nasty infections in their tattoos from the shops using distilled water to mix the inks, thinking it was safe. For a neti pot, you really need to research the source of water because you can kill yourself if you get it wrong. Boiling anything you use will always be safe, but it's a pain in the rear. I use a bottled water that has been passed through a small enough micron screen and UV sterilized so that it's safe.

Distilled can be used for saltwater mixes and is generally regarded as safe. Using a bit of dechlor would not be a bad thing. It really should not be used for freshwater though since it's lacking all minerals. Animals have adapted to needing certain minerals from the water they drink, and a dechlorinated spring or surface water source will provide these.