DIY Refugium

A refugium is an extension of a larger fish tank, constructed for the purpose of providing a safe refuge for fragile marine life forms. By keeping the refugium connected to the main tank, aquarium owners are able to run two tanks from one water filtration system; keeping costs low while enabling a greater display of aquatic diversity.

  1. Location

    • For the sake of convenience, the refugium should be placed as close to the main aquarium tank as possible. In an ideal situation, the refugium will be located directly below the main tank; this allows the sump pump of the refugium to have access to the main tank water, rather than unappealing surface water. By tapping the return line to the main tank's protein skimmer, placement of the refugium nearer to the ground allows gravity and a low-maintenance sump to circulate the water supply.

    Construction

    • To begin, situate a large acrylic of glass aquarium tank between the main tank and the sump. The sump adds to the potential volume of the entire system; neutralizing the consequences of nutrient accumulation and removing any foreign substances that may have been accidentally introduced into the system. The refugium should use a tank that holds a minimum of 10 gallons of water. Place 1 to 3 inches of live sand in the bottom of the refugium and add a few pieces of live rock work. These live materials are readily available at pet stores or aquarium supply stores. They can help get your refugium off to a great start as they contain and abundance of aquatic fauna and beneficial microorganisms. Fill the refugium with room temperature water that has been chemically treated for chlorine and has the appropriate amount of salt added (if necessary). Position the sump pump so that the overflow from the refugium is fed into the main aquarium. This will move live feeder animals, such as brine shrimp, into the larger tank at regular intervals.

    Population

    • Allow the refugium to stand for one week to stabilize before introducing any new elements. Then check the pH and temperature of the water and make any necessary adjustments. Once you have achieved the appropriate environmental conditions, add snails, worms, copepods or seahorses to your refugium. If you'd like to encourage the growth of macro algae, you'll need to add a powerful light source. A macro alga removes harmful chemicals from the tank, and it out competes less desirable forms of algae for nutrients, maximizing the biological filtration potential of the system.