the way you're setting up your tanks spells disaster to me... you should either stick with a lake/country of cichlids and get only compatable fish... do moar research...
How big is the demasoni? If he is not full grown then he will not show his full aggression. Your peacocks will not last once he is full grown. Its the equivalent of putting guppies in with an oscar when the oscar is 1.5" and then telling everyone it is fine because no one is being eaten at the moment.
my demasoni used to breed like crazy... i started out with 15 fish, then i ended up having like ten spawning fish... i was overwhelmed with pseudochromis demasoni... that was my favorite mbuna tank...
