help my parrot fish.

[brenners]

hi i have a tropical tank with two parrot fish in it amongst others ,one i have had about 7 years one i have only had for 2 up untill now they have got on fine but in the last day or 2 they have started fighting the younger one being the bully is this normal or what should i do ? the old one really is taking a beating please help.

[B00]

How long have they been together?
Have you introduced other fish to the tank?
Are you overstocked?

If the tank is too small for all of the fish the residents will start competing for space- and squabbles will break out.

The one being bullied isn't showing signs of illness or disease is it? If it is that could be a reason too- the other is seeing it's weakness and trying to finish it off, survival of the fittest etc etc.