The absolute max he would need would be a 20 gallon for just one frog. They do well with about 5-6 gallons per frog but like the extra space. I keep both of mine in a 10 gallon and they are about full grown, but I will be moving them to a 20 soon.
They like company but the older they are when you introduce a new frog the longer it takes them to get used to it. Mine took a few weeks before they stopped nipping eath other but now they are never far apart and are always sitting next to or on top of one another. Its kinda cute!
I cant remember, is yours a definite boy or girl do you know? The girls get alot bigger than the guys. The one I had before was the size of my palm!
As for other critters there are some fish they can be kept with, mainly community fish that are fast enough to avoid getting eaten and lack spikes or barbs. So plecos and such are out unfortunately. Im pretty sure they can be kept with different Xenopus species as well without too much hassle.
Hope the info helped! Antoher thing to look into should you decide to keep him is the food. I bought a jug of this special koi food that has lots of nutrients and stuff in it (Sho Koi is the food) and my little frog just exploded in size in just a few months. And they are both healthy as can be. Just a thought!
Anyway back to studying! Catch ya later
Erin
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1:0 Veileds (Gene, RIP Aurora)
1:1 Albino Clawed Frogs (Phedre and Jos)
?? Fire belly toad (Harold)
Various cats and dogs 