How many angels in a 55?

[Star_Rider]

Pairs forming have little do do with even or odd numbers.

all you need is a male and female.
having more fish just increases the chances you will have 1 male and 1 female.
everything outside the pairs are basically invaders/outcast. and all will be pushed away/ beat up/picked on.
the hope of having an even number or more fish is to help disperse the aggression.
but will eventually lead you to the same conclusion.. remove anything that has not paired.

 

[Lupin]

With angelfish, it's not necessary to even keep them in whichever number you want. You can keep one by itself just fine but certainly not discus as they behave on another dimension than the angels.