the little compartment where the fry go works great during water changes because the slits are high on the sides, and so when you drain the tank, it still holds and inch or so of water. however, the compartments are a bit on the small side, and will not hold large fish. also, at least in my one experience, when the mother released the fry, they had a hard time getting sucked into the little fry container (it needs to use an air bubbler to create suction). once she actually let them go, they would go into the bottom, and when they water tried to suck them away, they got scared and were strong enough to resist the current. so i ended up having some from in the little container, and some in the area below the mother. if i re-did the situation, i'd prolly just a large platic breeding box with an air bubbler and strip the fry into it. that or use a tank devider.