Although Puffers are small they should really be in at least a 30 gal IMO
. I wish you asked before you bought the hex 7 because a 10 gal
. setup is cheap. As far as fish, I would be careful adding any more than 4 small fish like tetras because of your bioload. There are not to many fish that require less than a 10 gal
, Where you have a 7, and a hex, I would recommend a Betta and maybe 1 other compatible fish. Maybe others will agree, or oppose because I have never had a tank this small except for a Betta.
How do you plan on cycling the tank? What kind of filtration are you going to be using?