My angelfish seems to have fin rot. I noticed it 4 days ago. I have a 50 gallon tank with 3 mollies, one angelfish, and one bristlenose pleco. The tank is cycled, I do ~20% water change once a week, and the water parameters look normal after testing them multiple times with my API master test kit. I did a large water change, then treated the entire tank with MelaFix and PimaFix for two days. I did water changes on both of those days and vacuumed the sand. I know the effectiveness of Melafix and PimaFix is widely debated, but I wanted to try something light before thinking about antibiotics. The angelfish got worse, so I quarantined her in a hospital tank and put in one dose of Seachem KanaPlex and now I'm waiting. Is there anything more I can be doing? This is my first time dealing with this problem and using KanaPlex. I plan to follow the instructions and dosage on the box. I have aquarium salt, but have never used it before. Would it be beneficial to try salt or anything else? Any advice would be appreciated. It's very difficult to research how to treat fish. There is a lot of conflicting information in these forums and on fish websites.