I know there are many medications out there that can be used to cure fin rot. But I am hoping to find a way of ridding it without harsh medications, as there are baby fish in the tank.

I have a twenty gallon tank with now two Flag fish (the third disappeared after the last water change) and some mollies. The only one that has been affected is the male Flag fish. I have been trying to treat it with Melafix (which helps, but is not ridding him of it). And now he is getting red line where his anal fin touches the body. Like I said, its only been him, and I have been treating this for some time. All other fish are healthy.

I haven’t tested the water since I figured the medications would affect the water quality. And I try to keep the tank at least 76, but due to sudden cooler weather here and there its been hard to maintain it.

Also, it’s a planted tank with shrimp of different kinds. I do not want to do anything that may harm either of those.
Yes, I keep salt in the water. For health reasons and the mollies. Sorry I forgot to mention that!