I've had a powder blue dwarf gourami for about two months or so. I think he may have had this dark patch when I got him, but it seems a lot bigger than I remember. Last week when I was watching him swim around it kind of jumped out at me for the first time so I am thinking it must be bigger or I would have noted it earlier. He is swimming around normally and eating normally. The only symptom is this funky spot. Is this a common thing for powder blue dwarf gourami or is he sick?