I find that with adf/acf sand is the miracle substrate!!! esp with adf....it is much easier for them to find their food (rather than having to poke their noses in the cracks between rocks or gravel). and it is much softer for their little bellies!
as far as tank mates you want gentle fish who aren't pigs! adfs hunt by scent, not sight like fish. this means it takes them longer to find their food and if they are housed with piggy fish...they most often will not get their fair share and starve.
one tank mate that I have found to be wonderful with adfs are baby black moor goldfish, slow to hunt due to their telescope eyes and very gentle and have HUGE personalities!
other great tankmates are hatchet fish, cories, smal neons, livebearers - the frogs love the yummy fry!!!
just make sure that you do not choose any fish that have a cranky temperment...the little frogs will be pestered.
just add in some fake plans and a couple frogs...and you will have very happy frogs!
broken up reptomin sticks and bloodworms make for a very happy froggy tummy....sinking food works best (reptomin floats) because most fish go to the surface to feed and sinking foods gives the frogs an advantage!
just never - never never NEVER - feed just flakes....it offers no nutritional value at all the ADFs!!