They will 'fight' if not enough territory is available or if they all favour the same piece of courgette (they're extremely fond of this). Get 1 male to two females if they are old enough to be sexed, otherwise just but 5 or so youngsters, grow them on and any you don't need move them on (back to lfs etc.). Make sure tank is big enough (I recommend 30" long for three adults of about 5" ea.) for territories. They're great fish Kitty and lots of fun to watch and will breed quite easily as well. Provide bogwood though because they munch on this to help their digestive system ( it contains a substance called Lignin) and is a prefferred resting place as well.