It does look alot like potting soil. This is actually soil from my property. We have about 10 acres of woods and the soil is super rich and very dark for the most part on the ridge I live on. I wanted to use this soil 1: due to is richness and 2: I know it is virgin soil. I mixed it up with some lichen and a few small rocks. I plan on building a pretty large terrarium from scratch in the next few months and plan on using this one for something else.
fantastic (first?) build! A few comments
1) I would *highly* recommend against using anything you aren't certain of, especially things from outside. Most of us will bleach, bake, freeze, and then some on things merely taken from other tanks, let alone outside....and I assure you we don't go through the trouble because we are just having crazy fun
These tanks are (generally) sealed off. This means what you put IN the tank will stay in the tank, and if the soil you took from outside had any live bacteria/bugs/etc (which I assure you it did), they are now trapped in the WONDERFUL conditions of your viv....to multiple and infest...
2) along those lines...they may potentially be harmful to your future residents
3) I don't know what your soil is composed of, but most standard soils don't last too long in viv conditions....do a search for ABG mix or substrate recipe and you will find some much more suitable recipes
3) that plant on the far left (and i think i see one on the far right too) looks like a Coleus? If so, you might want to check the toxicity on that...not too positive tho (on the toxicity nor the id
Excellent job on the layout and plant placement, it is very aesthetically pleasing. Normally I'd say you might consider getting some orchids or other epiphytes to fill out your back wall, but I really like the look of your wall...what is that thing on the mid-right side wall (to the left of your purple bromeliad)? in the brom closeup it looks like some type of wood I don't recognize, but from the full tank shot it looks like a really good stone wall