I got a beautiful betta about 2 month ago. He is healthy, eating, active, and colorful. This morning, I noticed that his fins were starting to rot away. It is not serious yet, and I tink I saw this case at the right time. I have had fin rot with my other bettas, and only 1 of them made it...

I would like to treat him and get him back to normal because he is 1 of my best ones.
I have done a large water change- cleaning the gravel well. I have only silk plants in there.
I have some aquarium salt, fungus clear, and maracyn. If I need anything else I will try to get it.
I guess I need to know the best way to treat him and keep him healthy.