I had a brand new angelfish tank that was just getting cycled and so I bought a new fish and didn’t quarantine it and wouldn’t you know they all got sick and I tried everything and I lost six of them before someone guided me towards Eyrthromycin. Few folks offered it, but ordered it after the first days dose I could already see a difference in that they were starting to get their fins unclamped and looking less dismal. If what you’re experiencing is a bacterial issue, This is good stuff. It works.