What is an Aquarium Refugium? What are the benefits? by Lev Ingman

A refugium is a separate aquarium, connected to the main display tank, this is used to grow algae. Usually a refugium is a separated area in the sump or a hang on the back addition. The reason you do not want to grow the algae in the main display is because it can get out of control and overrun your display tank. Also many species of tangs, which are common in reef tanks, will eat these types of algae. You want to make sure that your refugium has good flow, good lighting, and has a substrate to grow on. Usually a few pieces of live rock and a couple dozen watts of power compact lighting will work. Zooplankton, Phytoplankton, copepods, and anthropods will all grow in your aquarium and provide food for your tank inhabitants. The algae will also absorb nitrates, phosphates, and other organic waste products from the water. The algae will also oxygenate the water and will help balance your PH. If you have a sump, simply buy a cheap light, section off an area of the sump and throw in some algae or a mini mangrove tree. The algae will help keep your tank clean and will benefit the overall health of your system dramatically.