It's my first time building something like this, but I've wanted to spruce up a tank for land crabs for awhile now, so here goes.
I'm starting with a 20 gallon long all-glass aquarium (30" x 12" x 12").
Here's a picture of Clip the moon crab (gecarcinus quadratus). The white powdery stuff is just some calci-sand he's been digging in. He's still just a baby. I found him at a reptile breeder show this past weekend, crammed in a small plastic container with 2 other males. That's something you really shouldn't do. I've kept these crabs before, and they're highly territorial - 2 or more in too small a space will result in lost limbs or worse. Clip can back me up on that - when I found him, he was missing 3 legs on one side. Luckily he'll grow them back in the right environment, the next time he molts. I've had crabs regenerate legs before, but I've never started with one missing 3 legs, so hopefully he'll pull through.
Back to the paludarium.
There will be about 3" of brackish water at the bottom. The purple tube in the corner will lead to an external canister filter - I'm thinking of
this one from SunSun. I'm planning a waterfall at the opposite end of the tank. Those two circular things in the sketch are abalone shells - I have a couple, and I noticed they have small holes along one side, which I think will make a cool drip effect if I angle them properly.
To the right, I'm thinking of making two levels of sand for burrowing, held in place with glass dividers. I think I'll get the glass cut to size and beveled at a glass cutter's, and I might decide to sandblast it too, for a frosted effect. I'm planning on covering parts of it with slate, but I thought it would be neat to leave some of it translucent to see if I can view some of the crab's burrows that way. The glass dividers won't be solid all the way to the bottom, to make sure water can circulate. There will be a false bottom underneath the sand to make sure there's good drainage.
The brown sections are going to be filled with moss/coco husk/possibly soil. They'll also have false bottoms underneath.
Heat will be provided by a submersible heater, tucked away in the white compartment towards the back-center of the aquarium. The bottom of the white box will be open so that heat can circulate freely through the false bottoms of the other areas and the open water section at the front. To prevent the crab and/or feeder fish from disappearing into the false bottoms, I'm going to make a small moss wall to enclose the open water area - hopefully that will keep the animals out of the false bottoms while letting water circulate through. I'm also going to rig up the lid of the heater box so I can open it up, but the crab can't.
So that's the basic idea I've got at the moment - obviously there will be more to it than this, once I get to the decorating / planting stage.
I think I'm going to rely mainly on glass and slate for the structural pieces of the setup. Since it's a glass aquarium, I think using glass and silicone will make it more durable than trying to incorporate plastic. Land crabs can also be quite destructive as they mature, and I know they can easily pick apart wood and sometimes plastic, but I don't think they'd have such an easy time with glass and slate. I'm also hesitant to use wood for anything structural because I've had problems with mold in the past.
Anyone have any thoughts / ideas / suggestions?