Refugiums, small aquariums that either sit next to or hang onto an existing saltwater or reef aquarium, are used by a growing number of aquarists to continually cycle water into and out of the existing tank.
Typically containing aragonite live rock, macroalgae (plants), and a deep sand or mud bed, refugiums:
- Provide existing aquarium inhabitants with natural food sources such as phytoplankton and zooplankton
- Filter water naturally (dramatically lowering nitrate and phosphate levels)
- Stabilize water conditions (especially oxygen level and pH)
- Help control algae growth in the existing aquarium
- Add trace elements back into existing aquarium water
- Serve as temporary acclimation tanks for new inhabitants
Neighboring refugiums - those set up next to, or nearby, an existing aquarium - can also reduce the number of necessary water changes.
Hang-on refugiums are either an acrylic box that hangs on the outside of the primary aquarium, such as the AquaFuge External Hang-On Refugium, or a small acrylic box that attaches to the interior wall of the primary aquarium, such as the
Refugiums offer an ideal natural solution for enhancing and maintaining healthy conditions in an existing aquarium.