i keep my two in a five gal with two fw (be careful, there are also bw varieties) bumblebee gobies, and some ghost shrimp that were supposed to be food but didn't get eaten and are now too big to be eaten so they just clean up after the otehr fish (eat the leftovers). my two puffers are quite passive as puffers go, but even if they were more aggressive, there are plenty of plants and two caves for them to use to hide in and establish territory. not sure how they'd do with adfs, though if the puffers turn out to be passive enough, and the adfs are like they always are when i see them at the lfs (not doing much), you might get away with it. otos are a good choice though, and theyre neat little fish. i'd go with the ten though if you were you, then you could have 3 or 4 dwarf puffers and a couple of otos, makes for a more interesting tank. check out the pinned article about puffers in the oddball section for tank set up.
