Amazonian is on to it. If you keep the fry in a small tank (I keep them in a bare tank with low water level) and you feed them brine shrimp and microworm, they are always surrounded by food and eat heaps. As they get bigger and start moving around the tank more you can go to a larger tank. At this stage I use a much larger bare bottom tank with a sponge filter and floating plants. If you use a pilot light they will feed at night as well, and therefore grow quicker. So you may have to get another tank---what a bugger.