DIY: Refugium Light

Written by dr. samuel helms
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DIY: Refugium Light
Floodlights provide plenty of light for a refugium (Hemera Technologies/ Images)

A refugium is an area somewhere in the aquarium system that is free from predation. They are usually located in a separate container from the display aquarium, typically called a sump. Although refugiums do not have to be lit, adding a light allows you to grow beneficial marine plants (macroalgae) that will help remove nitrates and phosphates from the water before they cause a nuisance algae outbreak. Compact fluorescent floodlights are excellent for lighting a refugium and can usually be found at a hardware store. Choose a light and fixture rated for use outside so it is sealed against moisture.

Skill level:
Moderately Easy

Things you need

  • Floodlight
  • Power cable
  • Screw-in hook
  • Chain

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  1. 1

    Connect the wires of the floodlight to a three-pronged power cord. Match the colours of the wires, twist them together and thoroughly seal with electrical tape. It is best if the connection is outside of the sump area to prevent it from getting damp.

  2. 2

    Hang the floodlight above the refugium with a small plastic chain. Screw a hook into the wood above the refugium and hang the chain from it. This will allow you to raise and lower the chain to adjust the light. Make sure there is adequate air flow around the light to prevent overheating. Consider adding a small fan inside the sump area to keep the light cool.

  3. 3

    Plug the floodlight into a timer and plug the timer into a power outlet. Set the timer so that the refugium light comes on when the aquarium lights go out at night. This will help ensure there is plenty of oxygen in the aquarium at night and help maintain a balance of carbon dioxide.

Tips and warnings

  • Choose compact fluorescent lights over metal halides if you are setting the light in an enclosed area. Metal halides get very hot and could start a fire if not kept cool.
  • Make absolutely sure that there is no risk of the light falling into the water.

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