My dwarf gourami has had a strange bump on his head and has been getting worse for the past week. Ammonia is .25 ppm and nitrite and nitrate are <5 ppm ph is about 7.8. Temp is 77f. 20 gallon community tank with 2 zebra danio, 3 tiger barbs, 7 neon tetras, 3-5 guppys(less than a inch) 1 rubber nose pleco, 1 angelfish, and 2 zebra snails. I have a 5g Quarantine I can set up.