I had a tank that I have set up for about 2 months with 4 glowlight tetras and a plec. All were fine. Two weeks ago, I then added 3 platys (1 male, 1 female and 1 not sure!). Anyway the platys have since become real bullies and are not allowing the tetras to feed! Any advice on how to solve this problem would be much appreciated and has anyone had similar problems?!