MAKE a breeder box out of a plastic disposable cup. That's what I'm doing now with my Endler fry. Take a cup and a needle and a lighter, heat the needle (be careful) and poke, um, maybe 35 holes in it (so small that the fry can't get out) and then chip-clip it to the side of the tank. It works, as you still get the heat and filtration, but will little or now casualties from the fry. Hope I helped!