The cycle begins when the eggs hatch and start producing waste.To introduce the beneficial bacteria, as the eggs hatch we start adding BioZyme, a product that contains both Nitrosomonas and Nitrobacter bacteria.The ionized form, Ammonium (NH4), is present if the pH is below 7, and is not toxic to fish.The unionized form, Ammonia (NH3), is present if the pH is 7 or above, and is highly toxic to fish.Fortunately, just after hatching the alevins are producing very little waste.Their waste is quickly broken down into either ionized or unionized ammonia.