Mexican red knee substrate idea

[Postmalone35]

I collect dirt from beneath the oaks in California. You can probably find what you need in your local forest.

 

[Marlana]

I use topsoil but add excavator clay by zoo med, to it for my tarantulas that like it dryer (and trapdoor spices that live in clay soils). You don’t add too much but it definitely helps make a more natural soil. Since you don’t add much, a bag goes a long way. And works wonderful for making burrows. But plain topsoil is fine too.