Thank you everyone; yes, his fins are rotting. I have him in a quarantine "tub" with air stone and heater and one small driftwood. He has eaten a couple of pellets this morning. Used Fritz water conditioner and pH decreaser in tub.. He seems to be slightly more lively; I did have hammocks and logs for him to lay on but he still stays on the bottom under the driftwood. Shallow warm clean water. Took his tank down again, will be starting over with new gravel. Will have to recycle. How do I know his fins have stopped rotting? Should I keep him in the "tub" with 4 inches of water until his tank is ready??Should I add some aqua salt? It's very clean. I THINK I had too much waste in the gravel, even tho I do lots of partial water changes. I got a new gravel vac that is amazing. Since I gave him Maracyn and Paracleanse treatments earlier, the fins should no longer be "rotting", right? I know hey take a long time to grow back. When can I put him back in his tank? He is alone; no plants yet. driftwood and hammock and catalpa leaf. I'm not giving up on this guy. He also was the ugliest, palest, most scraggly one when I got him and he has been well and handsome. Now he is weak, skinny, tattered, and still. Your thoughts are appreciated.