How to Build a Water Filter System for an Aquarium

One of the more challenging types of filters used in aquaria is the trickle filter. This filter, also known as the sump filter or wet/dry filter, is considered challenging because most fishkeepers assemble their own rather than buying the filters premade and prepackaged. Despite their challenging reputation, they are not impossible to build. Granted, they do require large amounts of patience and planning. But with some knowledge and a plan, these effective filters can be constructed.

Things You'll Need

  • Aquarium or acrylic box to use as a sump
  • Overflow box (available at aquarium stores or online)
  • Vinyl tubing (length varies based on your specific design)
  • Aquarium glue or acrylic glue
  • Planes of glass or acrylic for baffles
  • Filter media (blue floss, bioballs, nylon bags, carbon/zeolite)
  • Pond pump
  • Return spigot
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Instructions

    • 1

      Drain the top 4 to 6 inches of water from the aquarium. Hang the overflow box from the frame of the aquarium. Attach vinyl tubing to the overflow box and run it to the "in" side of your sump.

    • 2

      Glue glass or acrylic panels in place to make baffles. Since sump filters are aggressively DIY, the specific layout of the baffles will depend on your design. Baffles will help force water over your filter media, like a maze for the water. Allow glue or acrylic solvent adequate time to dry.

    • 3

      Add your filter media to the sump. This can include bioballs, carbon/zeolite, or blue filter pads. It's recommended to use some kind of filter floss or filter pads at the beginning of the sump to catch course debris.

    • 4

      Install a pond up-rated for 3 to 5 times the volume of your tank and sump-per-hour in the "out" end of your sump. Run a vinyl tube from the out pump to the return spigot.

    • 5

      Install any heaters, skimmers, pumps, and secondary filters in the sump. One of the best perks of a sump filter is that you can hide all of this unsightly but necessary gear under the aquarium in a cabinet.

    • 6

      Refill the aquarium. Add water to the baffles of the overflow box and fill the sump. Mark the level of the water on the outside of the sump with a marker and label the line "max fill." Top off any secondary filter and wait fifteen minutes.

    • 7

      Activate all pumps, heaters, skimmers and secondary filters. Mark the water level of the sump and write "max fill, pumps ON." This level should be lower than the previous line.