92g 3-Level Crystal Platforms Crabarium! (Pics)

[JediMasterThrash]

Here's page full of pics of the latest incarnation of my 92g crabarium:
http://home.comcast.net/~JediMasterThra ... allery.htm

Please see my "Lessons learned from a deep clean part 3" post for more details about the choices made in this tank.

This tank is an exercise in trying to solve all the problems I had with my previous incarnation (the Action Platform Crabarium). Of course each incarnation attempts to do that. The first Mystical Mountain tried to solve the problem of having enough room for multiple jumbo crabs and supporting main-tank molts. The second Mystical Waterfall tried to improve humidity with a waterfall and expanded on the success of the wicker baskets. But it encountered new problems, which was how easy the wicker molts under the substrate, and how ugly crab poos look in white sand. So the Action Platform solved that by having no organics in contact with the substrate, and using eco-earth to decompose the poos. Plus I had waterfalls and crushed shell in both salt and fresh water in hopes of improving water quality through circulation and aeration and good-bacteria growth.

The main problem in the last crabarium was in fact the water though. I'll elaborate on it in the deep-clean post. Here's what I did this time:

First, no eco-earth near the water. So instead of mixing the eco-earth and sand half-n-half like I did last time, I did sand in the left/back half of the tank, and eco-earth in the right/front of the tank. So the water ponds are well buffered by sand, which doesn't dirty the water as easily. I recommend getting your eco-earth on-line, because PetSmart stopped carrying it, and PetCo stopped carrying the 3-packs, so you have to pay 5$ a brick (you can get 3 for 6$ on-line). I also propped the bowls about 3/4 inch above the surface of the sand to minimize piling substrate over the edge and getting it in the water. I temporarily have some small cholla there so that small crabs can climb up to the lip, but in the future I have plans for creating a ramp out of plastic mesh.

Second, no-more cheap-arse attempts at getting cycled water - they don't work. I broke down and bought two small filters - Duetto 50's. They cost like 27$ each in the store, but you can find them on-line for half that. They're really nice though. They're the only ones I saw that you can mount on their sides like that so you can run them in under 2 inches of water. They have 3-state filters. Mechanical (basically a sponge to trap debris), chemical (premium activated carbon), and biological (a spong below the carbon chamber that grows beneficial bacteria to absorb the ammonia and nitrates). It also has a nice 55gph spout that creates great surface aeration, as you can see in the pictures.

The instructions say to replace the filters (mech and chem, but not the bio) every 3-4 weeks. But the full replacement parts are like 4$ each. So instead I just bought this giant bag of cut-to-size filter foam and a giant tub of premium activated carbon for the same price, and those should last for a year or more.

The bowl the waterfall came into wasn't big enough for large crabs to dunk in, and it wasn't big enough for the filter, so I found a large tupperware at a garage sale for 25c, and removed the screws from the waterfall and mounted it in the tupperware. This wasn't an easy task. The tupperware was about 5/8 inches deeper than the bowl, so there was a gap on the bottom. I took one regular CD case and one slim CD case and stacked them under the waterfall to support it (you can kinda see the corner in the picture). This prevents it from rocking forward. The other problem I discovered is that without being screwed down, the darned thing floats! As soon as I put water in, up it bobs. So I put those smooth stones from a tabletop fountain into it to weight it down. Then it still isn't completely stable, so I have those two big sponges in each corner to further help anchor it in place. Well, despite quite an effort, it seems to be working well now, as you can see in the picture. Several strawberries have been climbing all over it and some little E's have been playing roll-down-the-mountain and it's still standing.

I would like to try putting some marine hermit crabs in the salt-water bowl. I've heard of other members doing this. I was hoping that with the quality filtered/cycled water it might work.

Another issue was the depth of the substrate. I'd always been an inch or two shy of my target 6 inches. But this time I didn't compromise. I have a solid 6 inches of substrate, as you can see. That's 3 bricks of eco-earth plus 3 full bags of playsand (2.24$ each at home depot). I'm hoping it makes molting easier for the jumbos. I'd previously kept the substrate a little lower than I wanted because I had the water bowls on the bottom, and they're just 3 inches deep. But this time the water bowls are up, with probably 3-4 inches of sand under them. So if crabs do go under, they won't be trapped. I took a small level and smoothed out the sand with it to make sure the ponds were level so the water was equal on all sides.

I restructured the mini-cube parts to give easier walk-through ability (instead of having to walk around that giant X before), which allowed me to save space with it and create a cooler 3-level design.

I've got about 40 empty shells that go in the platforms. And I have 33 hermit crabs, including PPs, Es, Rugs, Cavs, Indos, and Straws to enjoy their new home!.