ReefPods are a tropical/subtropical species of benthic (live on substrate) copepod. These copepods eat detritus, left over fishfood, fish waste, plant debris and microalgae. If left alone they will rapidly populate a marine environment-your tank. They are small which makes them suited for many juvenile and adult organisms and are generally not harmed by pumps or powerheads. They are Reef Safe which means that they will survive in an aquarium and come from a fish free system which they have been cultured in for over 5 years. They are a distinct population which has been selected for over 5 years, to handle the conditions of an aquarium setting. There are 100-200 per package along with chaetomorpha macroalgae, some microalgae (phytoplankton) food and natural seawater (treated with ozone, carbon, uv).We recommend several approaches to using the ReefPods. They can be added directly to the top tank. They can be added directly to a refugium. They can be placed in a jar, grown and fed out as desired. If there is a wrasse or mandarin living in your tank already do not be surprised if the copepod population does not take off. A ReefPod population that is flourishing will be evident by the moving specs on the sides of the tank either during the "day" or "night" cycle.A percentage of profits from the ReefPods are reinvested into either conservation or research concerning our oceans."