ok, so heres the story. this angelfish was the most docile fish in the world a week ago. it would stay in its corner, come out during feeding, dance around at the front of the tank when I came up to feed it, it was nice. about a week ago we put another filter in the tank, its a aquaclear ac70, it make a ton of bubbles. well the angel loves the bubbles, to the point where it practically guards them, any fish that comes near them get bumped, niped and chased away. we just moved the filter to the other side of the tank, where it was before the angel had pretty much claimed about 3/4 of the tank as its territory. now its got about 1/4, it still will chase anyone who gets near its bubbles. we just put a new fish in there, a dwarf gourami, hes about an inch. hes doing ok, but the angel really dosnt seem to like him and will come across the tank to get him, hes pretty fast and can evade the angel pretty well, but he gets him sometimes. the angel is being so agressive that when you put a finger on the glass of the tank it will try and bump it, also when I was rearanging and putting new decorations in the tank it hit my hand once also, it had tried to go for a few times before that. I dont know why the fish has become so agressive all of a sudden, any ideas??