Good advice, Shelly.


From the pics, it looks like there might be an ulcer, or a flex infection, on the fish.

Is there anywhere that he could have injured himself in the tank? A sharp decoration or filter, perhaps?

If it does look fuzzy, and like wet cotton, I would isolate and treat for flex.


As well, plecos need around 40 gallons each; they should grow to around 2 feet.

~Ash