DIY Sump

A sump is an external container of water connected to the aquarium's water system. In essence, it is a vessel of water that sits outside of the aquarium that shares the same water supply. Sumps provide several benefits to an aquarium. First, they increase the total water volume of the system and help stabilize water parameters, such as temperature and pH. Second, they provide a space for equipment, such as heaters and filters, that is usually not visible. Sumps are fairly easy to make yourself using items from a hardware store. For materials, use acrylic (plexiglass) or glass and avoid metals, as they may corrode and leach chemicals into the water.

Things You'll Need

  • Plastic or glass container
  • Return pump
  • Filter media
  • Acrylic sheets
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Instructions

    • 1

      Measure the space you have available for the sump. Common areas for a sump are under or behind the display aquarium. When measuring, make sure there is a 4-to-6-inch clearance between the sump and anything above it. This will give you room to work in the sump later.

    • 2

      Set a plastic or glass container in the measured area. You can use many different things as a sump, such as small glass aquariums, plastic buckets, feeding troughs and old wet/dry filters. Whatever you use, make sure it is clean and never contained something toxic, like paint.

    • 3

      Add baffles to the sump using acrylic sheets. A baffle is a barrier between one chamber and another (similar to a wall). Baffles force the water to flow under or over them. Cut the sheets to size and fit them between the side walls of the sump container. Usually, you will need three compartments or areas within the sump. The first area is where the water enters the sump. The second area is where you will place most of your filtration devices, and the third area provides a space for the pump that will send the water back into the aquarium (in other words, the return pump).

    • 4

      Plumb the aquarium into the sump. Common methods of connecting the aquarium to the sump are with bulkheads or a siphon. In either case, you want the water to flow from the aquarium into the sump while the return pump is on, but stop flowing when the return pump shuts off. Therefore, the water in the aquarium should flow over a dam then into the sump.

    • 5

      Install your return pump and connect it to the aquarium. The return pump will send the water from the sump back into the aquarium and provide the flow to start a complete cycle of water. Install the outlet from the return pump just at the top of the water in the aquarium; this way, it will not siphon water from the aquarium into the sump when the pump shuts off.

    • 6

      Add your filtration media to the sump. Good choices include sponges, bioballs, protein skimmers, granular activated carbon and phosphate sponges. All of these can be found at specialty aquarium stores or online.

    • 7

      Fill the sump with dechlorinated water (or freshly mixed saltwater) and turn on the return pump. You may need to add more water if the pump begins to suck in air.

    • 8

      Simulate a power outage by unplugging all of the devices at one time. Watch the aquarium and the sump closely to make sure the system simply shuts off and doesn't flood.