I am new to posting to this site, so I am unsure if I was successful at uploading the photos of my poor betta. Background and Water Stats: I bought my betta two days ago. I had him in a 20 gallon tall tank, with four platies, 6 cory cats, 2 snails, 2 dwarf frogs, and one male guppy. I was ready to separate him from the guppy if needed, but they actually did not pay any attention to one another. Water Quality : 0ppm Ammonia, 0ppm Nitrite, 5ppm Nitrate. My Nitrates were at about 20ppm the day I got him, so I did a pwc to bring it down to 5ppm before I put him in the tank. My heater is 50watts, room temp 75 degrees f, water temp stable at 78-79 degrees f. I use Seachum's Prime to treat my water. I do 25-30% water changes each week depending on water readings. Please Help! My betta went from a beautiful blue color with long flowing fins to looking very dull overnight. Some of his blue remains, but there is a huge spot on top of his body. It appears either he got nipped on repeatedly in the same general area...or perhaps trapped himself and fell asleep behind a heater?? I included a picture of when he was pretty yesterday, and two pictures of him today. The one picture I had to use flash for the picture to show up better. (Note: the lighting is also yellowish in the sick tank.) Either way, I'd like to know how I can best treat my betta. I have him in a 10 gallon hospital tank. I put 50 percent less then directed PimaFix and BettaFix. I know about the breathing organ debate but it seems like it's a 50/50 argument that goes both ways and I feel helpeless not doing anything. Water stats on sick tank : 79 degrees f, o ppm Ammonia, 0 ppm Nitrite, 0 ppm Nitrate.