u/FineAtmosphere9578

I need some help, it looks like my Betta fish is developing signs of fin rot. His fins have started to get a lot more stringy looking than usual. I’m gonna start with a 50% water change but what else should I do any medication’s anybody recommend recommends how I should treat it to prevent it from getting worse please help. His water parameters are all fine. I do regular water changes as it is.. so I’m not really sure what’s up?