Re: Minimum space?
overall space is less important than how you design said space.
That being said, I think a 20 vert is fine, BUT you will need to constantly add microfauna in the form of springtails to keep the in tank population from crashing
Also, you want to make sure there are adequate deposition sites, hiding areas and calling areas to choose from, not just one that may be less than optimal
Really, I think youd be better served by an 18x18x24, but it can definitely work
I like frogs with racing stripes