I have just bought a breeding pair of discus, they were introduced to the tank last night, however, the biggest of the pair and the existing dominant discus have jyst bickered constantly from the moment the pair was introduced. They are beating their bodies and headbutting each other, will this settle down. Also is the discus pair bond strong? And lastly i have now got 6 discus (ay about 5 - 5.5"), cold i add another 2 as they still seem really shy> (tank is juwel rio 400 - 60 x 30 x 24").