I say two because there were 2 in the tank and they both seemed fine[granted, this was a HUGE tank in comparison to the hex but eh]. So far, the chasing is kept to a minimum and they seem to be eating regularly and acting like epic little puffers should.
But, should I be worried? I've always read these guys need 5gals alone but when I saw their size, I decided an established tank with lots of cover[still need a certain type of plant] was more important then a bigger tank. I'll keep up with my WCs, but do you see this being harmful for them?

Oh yeah, they live with my final RCS colony ... the puffer guys have been epic so far and have only eaten snails!
