Aggresive Discus

[RDavies]

I now have 4 Discus (will be 6 tomorrow when I leave JTs house). I started off with a 4.5cm red turq and 5cm blue turq who started out friendly with each other. Last week when I added 2 8cm fish, all 3 of them started to bully the 4.5cm red turq. Usualy what happens is the 5cm one gets pushed out by a bigger fish, then he goes looking for the 4.5 cm fish to push around. The smaller bullied fish usualy hides away with fins retracted, while the others, including the 5cm one mingle a fair bit with fins held high.
Are there any factors which increase aggresiveness, such as temperature, conditions, feed etc?

[lpiasente]

They are just sorting out who is boss, they will settle down.