Agressive towards each other???

[Pletchetero]

I have had my discus for a few weeks now and I added two (royal blue) at first and got my next one a few days after. The first two seem to be very aggressive towards my new discus (Marlboro Red). They keep him/her behind a plant in the corner. Is this normal?

[waitaki]

yes it is normal behaviour. Discus are best kept in schools of 5.
How big are they?
If the 2 are bigger than the red then the red could be in trouble.
If you have any driftwood in the tank keep moving it around.
Don't separate the red - if your tank is big enough get another couple of discus. (Quarantine them first though)

[Pletchetero]

I am planning on getting a few more. But I noticed this behavior and it worried me.

[Pletchetero]

And they're all at least 3-4 inches.