How to Set Up a Sump Pump Filter Box for an Aquarium

Written by carrie terry
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Sump boxes, or refugiums, are smaller aquariums that are separated from the body of the main tank. As such, they are independent tanks that usually sit below or behind the main tank, share the aquarium's water and house equipment or smaller creatures that wouldn't be safe in the main tank. Set your sump pump filter box behind the aquarium to hide equipment, or next to the aquarium to house animals.

Skill level:

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Things you need

  • Sump pump/filter box/small aquarium
  • Drill
  • Plastic hose
  • Sealant
  • Filter/pump system
  • Valve

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  1. 1

    Find an appropriate place to locate the sump pump filter box. The box should sit below the water level of the main tank, to take advantage of gravity and become a part of the aquarium's filtration system. Put the refugium in a place where it can stay for the long term.

  2. 2

    Drill two holes in the side of your aquarium, in equal diameter to the plastic hose you're using. The hose should be long enough to run from the main tank to the sump pump filter box without kinks. Insert a length of plastic hose into each hole in the main aquarium, with minimal hose extending into the aquarium itself. One hose will transport water from the main tank into the sump pump tank; the other hose will return water from the sump pump to the main tank. Use the sealant around the outside of the holes, to secure the hose and waterproof the holes.

  3. 3

    Set up your pump and filter equipment in the refugium tank, per manufacturer directions. Attach the end of one of the plastic tubes to the filter/pump set-up per the instructions that came with your equipment, to pump water back up to the tank. Place your squeeze valve at the sump pump end of this tube, to control the rate at which the pump returns water to the main tank.

  4. 4

    Set up the second plastic tube. Attach the tube to the alternative outlets of your pump following manufacturer directions, so that water will be sucked from the main tank into your sump pump filtering system, to complete the water exchange and keep the water levels even in both tanks.

  5. 5

    Use the valve to moderate the rate of water exchange by opening and closing it to make sure the same amount of water is going into and out of the sump pump box at all times. Always keep the water level in the sump pump box even, or you'll risk overflow.

Tips and warnings

  • Raise algae, young fish and feeder organisms in the sump pump filter box.
  • Always set pumps up when your aquarium is empty. Turn the pump on after you've filled the system with water.
  • Plastic hose meant for fish tanks is available at aquarium supply and pet stores.
  • Organisms and sand can become caught in the suction of the pump if it's too strong.

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