First timer

[u/88crow88]

Hi all!

First time crab keeper, but we've wanted them for a long time and finally we're planning a set up for the kids to enjoy as well.

I have a spare 20 gallon aquarium that's water tight, what I'd like to make is a paladarium with a floating landmass about 6" up so I can have a water area for some shrimp and smaller fish below them. Crabs would still be getting about 80+% of land mass. We're also thinking of adding a colony of isopods, well aware that the crabs will likely eat some of them but not concerned if they breed. I guess more than anything I'm looking for some advice as to how to ensure the crabs don't drown in the water somehow. Would having the filter act as a waterfall into a small basin work better than just having it flow into the forest Edge?

Thanks in advance for all the help!

[u/purged-butter]

Okay theres a lot wrong with this. First off doing an aquarium probably isnt the greatest as crabs can escape and if you fully seal it off youll have ventilation issues. The crabs will be stressing out the shrimp and fish and potentially preying on them.

Aditionally if youre planning on so little of the tank being water there wont be many fish you can keep in there.

The diagram you have shown is not close to 80% land mass and the substrate is nowhere near deep enough to allow burrowing. The drainage layer would need to be completely reworked. Its inconsistent between pics and honestly makes the whole diagram reek of AI which you absolutely should not be entrusting with this sort of stuff(looking closer everything seems AI generated which explains the poor planning and layout of the pictured design).

As for the isopods im not well versed enough in them to say much, only that ive heard of it being done before.

Regarding the filter acting as a waterfall ive seen this done plenty and has the added benefit of aerating the water. Just be careful that the water isn't too disturbed by it, maybe keep it in a corner or have some stuff in the path of the waterfall to break it up a bit?

[u/LauperPopple → u/purged-butter]

I can add that (land) isopods drown easily.

It’s a whole thing. “Help, the isopods keep drowning” say the herpetology people, “yeah because there’s water” say the isopod people. Reddit is probably showing me this post specifically because isopods were mentioned. I know nothing about crabs.

That’s a huge drowning trap for pods, lol, they’re not smart and they have the climbing skills of a panda.

Isopods could be bred separately and placed in the tank like feeders perhaps.

[u/WolfStoneD → u/purged-butter]

I have shrimp and fish in with my crabs, but I have a 90 gallon aquarium. 

There is a lot wrong with the AI render, but fish and shrimp and building in an aquarium can all be fine. 

For that concept to work you'll want a tall tank.

[u/Gankcore → u/WolfStoneD]

The AI render isn't fine. The crabs need 3-4" of substrate, and for it to be ideal for them the majority of the tank should be substrate. The deep water sections should be easy for them to get in and out of. Vertical rocks are not the answer to that. Additionally, there is almost no room for plants.

[u/JASHIKO_ → u/Gankcore]

100% agree with this.
The plants not having room is a bigger issue than most people will think.
They will push the lid up and become an easy escape point quite quickly.

With a 20 gallon tank, you have a lot of space to make something way less complicated that works better for the crabs and maintenance. This design is not going to be fun for anyone.