One of my 5 Angelfish has been coming to the top for air and I don't really know why. Its the only fish out of my 15 Cardinals, 6 Sterbais and 4 other Angels doing this. I just noticed this while doing some maintenance. I quick threw an air stone in there to see if that helps. Its a heavily planted low tech 75g aquarium so shouldn't oxygen be prevalent? My Fluval 406 spray bar is below water level creating no bubbles at all. Could this be the problem? That was the only thing I can thing of but if the water level is at or below the spray bar it seems like it creates to much of a current in the tank. Any help is appreciated.