So my (single) Mossy is in quarantine and I have many different tanks laying around. So what are your thoughts...

Do I build in the 10 or the 20 tall?

My idea thus far...
A karst like cave along the shore line of the tank with a hill of plants towards the top...slow water feature dripping over the top of the cave and into the water (like many caves I have been in).

I always hear that limestone is bad to use in vivs, but if the species is from limestone streams, would it be useable?

I am thrilled to be building this and I need it too. Suggestions....now go!