I kept the substrate that was in the cup from when I got it from the shop; figured what they used would be fine for the time being, and I sure hope they didnt put potting soil in it lmao. Waiting on the new acrylic enclosure I got, should be here like Tuesday, when that comes imma snag some of the soil mixture from my main terrarium which has reptisoil in it. I sprinkled some gravel in because I put some small pieces in the bottlecap water dish in there so it wouldnt drrown in it