I have the background on, also the sides are done (but that will be in a later photo). Its going well, so far no problems.

The far right end will be a rocklined pond, separated from the "dirt" substrate growing area by a fossil coral waterfall in the middle that will have water pumped over it by a Little Giant pump. A piece of rubber pond liner under the coral will help keep the water largely directed to the pond area

Here is a link that might be useful: 55 gal terrarium/vivarium