Cupramine is an acceptable copper medication for most fish species. Most aquarists use hyposalinity with puffers, to the best of my knowledge.
Cupramine medication recommends a two-week treatment with the medication. You then hold the fish another 6 weeks in QT to verify it is free of Marine Ich. In this respect, the copper treatment is shorter.
Both treatments can be extended if, during the post-treatment phase the disease shows up again. But if each treatment was successful the first time around, the copper treatment is faster. The copper treatment is also more stressful for the fish. Some fishes refuse to eat during the treatment.
I'm not sure Cupramine is suitable for puffers. You might post a new thread and ask that specific question.
