I've only had my betta for a couple weeks and since day 1 I've noticed the area under his gills is miscolored. He's red with purple highlights, but his scales are kinda gray behind his gills and before the first set of bottom fins. The lower portion of his jaw also has this discoloration It's hard to get a good look. Everytime I put my face up to the tank, he flares his gills and bumrushes me, making it hard to get a good look. I want to say it almost looks slightly fuzzy like maybe a fungus. It's hard to tell. He's in a 1 gallon hexagon tank now. What shall I do?