Here's my 18x18x24 exo terra vivarium housing 2 dendrobates auratus 'costa rica'. It's been set up for about 3 years now, and I recently trimmed out about 90% of the ficus pumila that was taking over the tank, so it has some time to grow in again. Here's it before trimming:
Here's a pic of one of the two females after the trimming (no one has called in 3 years so I'm just assuming at this point):
Also, I'm almost done with a 24x18x36 exo terra build for a group of dendrobates leucomelas (not sure which locale yet). This weekend, the siliconing/coco fibering of the background will be finished and I can start planting. I'm going to order another misting system soon, and more plants in the spring, but other than that I have all the lighting, soil, and a good chunk of starting plants I got either from repticon or from cuttings from my other tank.
Also, here's some of the plants I have so far in a grow out tank (I got more at repticon and in the mail)
Who knows, maybe one day I'll make a background for the crab tank with spaces for the shower caddies, or even my own self made second level. I would just really need to get the right material that they wouldn't be able to scrape or pick off. A dry-lok background might be promising.
When you've been crabbing for so long, you don't even know how many crabs you have now...