This is one of my oldest and favorite hap.Ill tell you what i know about my water.Ive always kept one tablespoon of aquarium salt,my water temp is 83.Nitrate 40ppm,ammonia 0,nitrate low,ph 8.0.Looks like someone spill pen ink on him and his top fin looks tattered and black,Sorry about the bad pics but there all i got.The only thing thats diffrent lately is i added a new filter.I paniced and dosed with melafix and thats all ive done so far.I do two water changes a week and use prime.Someone please advise on next step or what this is.
And yes the new Fluval 404 has 4 brand new bags of carbon in it.