The Plankton Reactor is an identical 2.5 liter cultivation unit to the Plankton Light Reactor, without the light. When you supply the Plankton Reactor with phytoplankton from the Plankton Light Reactor and an air bubble source, you can double the number of rotifers in a culture in as little as four days. Rotifers (Brachionus) are an excellent small zooplankton food source and a common zooplankton used in this second stage culture. Using a second Plankton Reactor you can feed a portion of your rotifers into a third culture of larger zooplankton or 'pods to further enhance your ability to supply natural food items from across the food web, on demand.