one of the big fry is definitely a boy, can now see the colour on the lower fin. Nice to see them developing now, and how the dynamics in the tank change. The smaller fry get chased out of the feeding zone by the bigger ones who are in turn chased by the adults. The male who was the smaller bullied one has become the bully, he rounds them up and zaps off again. Am thinking that when I can tell the new females are definitely females, I will pass on my big boy and let the new little boy grow and that will give the female a little rest while he preparing himself for his destiny...!!