I just noticed this white stripe down one side of one of my guppies. Sorry it isn't the best picture. My water is amm 0, NO2 0, NO3 5. It doesn't appear to be fuzzy, it starts at the top fin and is all the way down the side of the fish. Has anyone ever seen this or should I just watch it for a few days? In this 10g tank is 4 guppies, 5 neon tetras and some ghost shrimp.