Considering they are mostly meat-eaters, I don't think you need to worry about your macro-algae. If you could get a photo of the puffers at your LFS, they can easily be IDed here. If they are not Ceylons but indeed F8s, then you couldn't keep the SG high enough with them to support SW algae.
its not just a matter of handling bioload, which is the only factor for some fish keepers, but also space for their wellbeing. YES!!!!!!!!! :hyper: Now that I see how much happier my fahaka is in his new 180g (from a life in 125g), I so want to repost all the minimum tank sizes on our Pufferpedia.