Let me see if I can remember.
Maracyn is Erythromycin and treats mainly gram + infections.
Maracyn 2 is Minocycline and treats mainly gram - infections
Maracyn TC is Tetracycline. good for fin rot, and is broad spectrum.
No idea what Maracyn plus biospheres is.
TriSulfa is a combo of a bunch of sodium sulfacides or something like that, broad spectrum I think.
A lot of people use Maracyn 2 the most, because most bacteria diseases (which are what these are for) are gram negative. Some people use both Maracyn and Maracyn 2 together to provide a truly broad spectrum treatment. I've seen Tetracycline suggested mainly for fin rot. Never used TriSulfa, but it sounds good. It's not antibiotics, so I would assume it has less tendency to mess with water quality than does the others that are antibiotics.
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