Determining gender!

[privet01]

Simple is good, IMO. Gravel isn't bad, I use it in my 10 gallon viv. Just make sure it's large enough that it can't be swallowed. 1/2" or bigger is what I use. Marinecrab is correct that they can ingest the smaller gravel and die.

I like your setup for it's simplicity. Hard to tell what your water level is, but I'd recommend a deep area where they can submerge themselves entirely. Say 2 inches or better.