i would advise you not to use breeding boxes/nets. they put way to much stress on the pregnant femal and may caus here to abort. insted use a seperat tank and put the female in there and when she is done put here back in the main tank. you are going to need another tank for the fry anywase as my platys mollies and swordtails all give around 20-40 fry per fish. and you cant raise 20 platys or mollies in a breeding box.