How to Build a Refugium Tank

A refugium can be a valuable tool in a fish tank setup. This secondary compartment shares a water supply and filtration system with your main tank, but can provide a refuge for small animals, a place to raise food sources like plankton and even a storage area. To set up a refugium tank, start with an old, unused fish tank.

Things You'll Need

  • Secondary tank
  • Power drill
  • Plastic hose (two even lengths)
  • Sealant
  • Substrate
  • Water
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Instructions

    • 1

      Empty your main tank of animals and water, and plan your setup. The refugium should be smaller than the main tank, and there should be room for it to sit beside, behind or below your main tank. Deciding on the location now will make your job easier, as moving the tanks after they've been set up and filled with water is difficult.

    • 2

      Remove and rinse out your pump and filter system. This equipment will now be housed in the refugium. Set this equipment to the side for the time being.

    • 3

      Drill two holes in the back or side of your main tank. These holes can be anywhere; there's no requirement for them to be at the top or bottom of the tank, though putting them near the bottom will increase filtration, as sediment naturally drifts to the bottom of the tank. Fit the two pieces of plastic hose into these holes, which should be only slightly larger than the hose. Secure the hoses to the side of the tank using sealant.

    • 4

      Place your pump and filter in their desired location in the refugium. Attach the free end of one plastic hose to the pumping function of the pump. Attach the other plastic hose to the sucking function. Connect the pump to the filter, per the system's standard requirement. This setup will now suck water from the main tank, push it through the filter, store it and pump clean water back up into the main tank. Make sure that the hoses do not have any kinks in them, as this could cause problems. Do not turn the system on yet.

    • 5

      Fill both tanks with de-chlorinated, treated water, and turn on the pump and filter. Monitor the system for leaks and overflowing, and give the entire setup an hour for dust to settle and be filtered out before you put your fish back into the tanks.