I have a 3.5 gallon tank with a Gourami and a blue Glofish. I have had the Glofish for over a year. Many months ago, I noticed a tiny milky Coloring at the base of his bottom fins. I had him with a Betta that kept attacking him so I moved that guy to a different tank and got the Gourami as his tank mate so I assumed this was related to the harassment the Betta gave him. At that time I could tell if t was just the Coloring of his fins. Over the last 6 months, it has gotten bigger and is definitely raised and it has now spread to his back fins. He seems to be very hungry as he swarms when I put food in and won't let his friend get much. Also,his mouth constantly opens and closes (like a dog panting)but he does not go up to the surface for air. I do not see him rubbing himself on anything. Any idea what it could be and how to treat? So far the Gourami does not show signs of disease and they have been together at least 6 months. I have 3 tanks going right now - the other 2 are Betta's. I have had for almost 2 years. I do a 25% water change every weekend. This tank was my first and has been up and running for almost 2 years.