Hello, my 6" NTT about to die on me. Got this guy when he is about 3" and all of a suddenly he got some fin rot and cloudy eyes and not breathing normal. He was in the 240 with 22" black arow and 4 frontosa and some med catfish. No other tankmate picked on him. the tank had been running trouble free for years. 30% water change weekly with aged water. Currently he's in the 55 gal grown out tank. I put in 1tbs of salt per 10 gal of water and some fungus med. I know some of you have had your dat die of unkow reasons. Hopefully someone know of something else that could help please post. thanks.