So I got Sam yesterday from a store, and today my brother said he looked lifeless, so we had a good look, and he has the below spot on him. I think he has fin rot because his tail etc is curling at the ends. I've never really had fish before, and my brother while having a large tropical tank, hasn't really dealt with Siamese fighters. We've got some Melafix, but I don't know if its the right thing or what.
Please help little Sam.
This was him yesterday when I got him (same side)
This is him tonight (had him 24hours now), I've just moved him so I can clean his tank.
I'm also about to give his tank a clean, and hope that helps a bit as well.