I'm hoping someone can help me diagnose an illness with my tropical catfish. He's a 13” Pleco (I'm not sure the species), 15 yrs old, who seems to have some sort of infection (see pictures).
Details: My pleco has some white sploches on his stomach, at the base of his fins, and around his gill openings; and also a white film over much of his dorsal fin. I asked at my usual fish store and they thought it might be a fungal or bacterial infection, but couldn't get more specific than that. It doesn't have the puffy, cotton-ball look that I have read about for typical fungal infections. It more looks like someone was coloring on his with a white crayon.
In the pictures you can see white stuff around the bottom of his gills; near his left shoulder; centered between his pectoral fins; and on his dorsal fin, esp the front part.
Treatment so far: Last Sunday (8/7/15) started treating with API-brand Pimafix and Melafix, 5ml of each/10 gallons/day, as recommended by the fish store. Did a 25% water change yesterday, as per directions. The fish store also recommended adding salt to the water, but the tank also has some Coolie Loaches, which are supposedly very sensitive to salt, and so I am hesitant to do so.
The Pleco's condition doesn't seem to have gotten worse since starting the treatment, but hasn't gotten any better.
Background: We had to move my Pleco quickly to get out of the way of a wildfire. I was out of town at the time, and he was not moved carefully. I'm afraid the whole thing was extremely stressful, and he may have been injured either by being picked up or by banging against the transport tank. There were no visible wounds, though, and it was several weeks until the first white spot appeared.
He's currently in a friend's tank. The friend has added a few new fish after he moved in but before we noticed the white splotches. It's a 55gal freshwater tank, planted with anubias, duckweed, banana plant, and some other plants. Other fish: 3 Otocinclis, 2 Coolie loaches, 1 baby gyrinocheilus.
Water test as of today showed: Ammonia 0, Nitrite 0, Nitrate ~5ppm. PH is usually around 8.2. These are pretty much the same conditions he was in in his old tank before the wildfire, though that was a 75 gal and I never managed to keep the nitrates that low.
I've had this fish since I was ten, and he means a lot to me. I'm rather terrified. Any advice you have would be greatly appreciated!