Substrate for a single african dwarf frog

[xXInkedPhoenixX]

Hey all, I'm going to be setting up a 3 gallon tank for my Mum for Mother's day she's been wanting an African Dwarf Frog for a long time I took her to the LFS with me scoping it out for my Oto babies and she lost her mind when she saw some albinos. It will be the only occupant along with some plants maybe a nerite once algae is present but I don't want to go overboard since it's a small tank. She's had them in the past (in less than desirable set ups, no filtration bowl type scenarios but be nice she really didn't know better thanks to LPS) they lived quite a few years shockingly and were active and seemingly healthy. Anyway, we're going to do better this time. 

My 3 gallon quarantine tank is the same as the one she has so I can jumpstart it from a filter currently in my tank that hasn't been exposed to any sick fish. 

I think I'm just going to get some Anubias species and either attach it to rock or driftwood so it being a plant substrate isn't as much of an issue. Should we do sand or gravel? I see some sites recommend sand and mention Carib Sea Super Naturals Crystal River Sand, but say if you go with gravel to choose larger so they don't swallow it and Spectrastone Shallow Creek Regular gravel was recommended. Any thoughts?  

Edited May 2, 2021 by xXInkedPhoenixX

[Colu]

I have never kept ADF but I think sand would be the way to go