How to Set Up Refugium With Sump for Aquarium

A refugium is essentially a refuge for aquatic life forms you want to protect from the conditions and inhabitants of the main tank. Refugiums have a variety of uses; they are ideal for cultivating algae that help reduce the nutrient levels in the main tank or they can be used to grow small organisms such as infusoria or zoo-plankton to feed the main tank. Building your own refugium is a ideal way of getting exactly what you want at a fraction of the cost. Creating a sumped refugium saves space and keeps your equipment tucked away under the tank.

Things You'll Need

  • 20-gallon acrylic or glass tank
  • Sheet of acrylic or glass
  • PVC pipe
  • Hand-saw fitted with a plastic or aluminum cutting blade
  • Aquarium silicone
  • Acrylic drill
  • 2 submersible pumps (100 gallons per hour flow rate)
  • Flexible plastic tubing (compatible with pump outlets)
  • 2 PVC 90 degree elbow joints (compatible with plastic tubing)
  • 4 sucker and bracket pairs (compatible with diameter of plastic tubing)
  • Small desk lamp
  • 24 hour mechanical timer
Show More

Instructions

    • 1

      Measure the length and width of your refugium sump tank and mark out a section with those dimensions on the acrylic sheet. Clamp the acrylic to the workbench and carefully cut the section out with your hand saw. Make sure the acrylic does not flex as you work. Sand down the edges once the section is complete. This will be the lid of your refugium sump.

    • 2

      Measure a circle in the acrylic lid that is the same diameter as the PVC tubing. Place the circle to one side of the lid, about four inches from the edge. Cut using your acrylic drill and sand the hole created. Make sure the tubing fits snuggly. Measure and cut an identical second hole on the opposite side of the lid.

    • 3

      Measure out a small section of acrylic that will comfortably fit in your hand. Clamp and cut as per the method in Step 1. Sand down and check that it fits comfortably in your hand. You can carefully use a chisel to create a rough surface, as this makes it easier to grip.

    • 4

      Measure the center of the acrylic lid and use the aquarium silicone to glue the handle perpendicular to the lid.

    • 5

      Place your refugium in the desired place under the main aquarium.

    • 6

      Fit one pump into your refugium sump and attach the plastic tubing to the outflow. Run the tubing from the refugium, through the hole in the refugium lid to the top of your main tank. Make sure the lid of the refugium is fitted snuggly to the top of the refugium and cut off the excess tubing.

    • 7

      Join the PVC elbow joints to create a "U" shape and silicone together. Attatch to the free end of the plastic tubing and silicone in place. Hook the U-bend over the side of the tank. Add aditional tubing as necessary to reach four inches below the water line in the main tank.

    • 8

      Attach a second line of tubing to the second pump and place in your main tank. Run the tubing from the submersed pump to the second hole in the lid of your refugium and cut of any excess. Silicone the free end of the tubing over the hole.

    • 9

      Allow the silicone to dry; this could take up to 48 hours. Always follow the instructions on the silicone packaging.

    • 10

      Place a 4-inch deep bed of sand into the refugium. To seed the sand with aquatic life, use some sand or gravel from your main tank. Fill the refugium with mature water from the main tank. Top the main tank as needed.

    • 11

      Place the desk lamp under the tank so that it illuminates the refugium. Set the socket timer to 12 hours and plug the lamp into it.

    • 12

      Plug both pumps in and turn them on. Check that the water is flowing at the correct rate. Plug the desk lamp in and turn in on. Monitor the refugium and main tank for several hours to ensure the water levels in both are remaining constant. Your refugium is now ready to be stocked with your choice of micro-organisms.