What could I do with my 1.5g it's empty because I moved the scarlet badis to a bigger tank. What you think about some dwarf frogs? I'll probably just put a small cave in it or something maybe some sand don't know yet.
I would do some shrimp- 1.5 is pretty small. I kept a betta in a 1.5 for a little while because I didn't have any other tanks to put him in and he seemed totally fine, but it is a little stretch. The only concern with African dwarf frogs would be the food polluting the water quickly-- they aren't super clean eaters and I have noticed that they have a tendency to ignore food!! 3 gallons is recommended for an adf, but it is totally do-able.
But but!!! I think shrimp would look really sweet In it! You could do a mini aquascape and little baby shrimps!!