True, but all of the products mentioned are perfectly safe with puffers, I can assure you. I used all of these back when I worked at the LFS and never once did I have an issue with them. On the other hand, I also used melafix on several occasions. I never once saw a particularly favorable effect. I prefer to stick to tried and true antibiotics. Beyond that, those dispersion rates are unrealistic. It is, however, important to make sure the fish gets plenty of the antibiotic ingested either way so that this effect is lessened. While topical application is undoubtedly more effective (always is for external problems), I would honestly only go the topical route when absolutely necessary, as it is even more stressful to the fish. You also run the risk of opening the sites for further infection. More of a last resort than anything and I don't recommend it unless the infection is very severe. Again, though, treating in a bath in a QT is still the preferred method overall in terms of less handling, etc. Not to mention that kanamycin is more effective orally as opposed to in a bath, as more is absorbed overall. I don't really want to argue the point too much, however, so I'll let you decide instead of going back and forth.
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