Homemade Bio Filter for a Pond

Constructing a homemade bio-filter in your garden pond is an inexpensive way to provide clean biological filtration to keep your fish and pond plants healthy. Biological pond filters maintain water clarity and provide a place for beneficial organisms to grow. Commercially manufactured bio-filters work well but are expensive. The basic materials needed to make your own bio-filter are found at home and garden centers or hardware stores. Creating your own bio-filter for your pond will give you the same results as a commercial model for less than half the cost.

Things You'll Need

  • Plastic bucket or container with snap-on lid
  • 6-inch-long PVC pipe
  • Utility knife
  • Plastic window screen
  • Silicone aquarium sealant
  • Small rocks or gravel
  • Plastic whiffle golf balls
  • Plastic pot scrubbers
  • Thick quilt batting
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Instructions

    • 1

      Cut a window in the lid of a plastic bucket or container, using a utility knife. Leave an edge of at least 2 inches intact around the edges of the lid.

    • 2

      Cut a piece of plastic window screen large enough to cover the entire window in the lid with at least 1 inch of overlap on each side of the window. Apply the silicone sealant in a thick bead around the underneath edges of the window. Lay the screen on the underneath side of the lid and press into the sealant to secure the screen to the lid and cover the entire window.

    • 3

      Trace the outline of the opening of a 6-inch-long PVC pipe on one side of the plastic container 2 inches up from the bottom. Cut out the circle with the utility knife. Insert the PVC pipe piece into the hole so that 3 inches of pipe is inside the bucket and 3 inches remains outside. Seal the pipe into place with the silicone sealant and allow to dry.

    • 4

      Pour a 3-inch layer of small, clean rocks or gravel into the bottom of the container to cover the PVC pipe. Add a layer of plastic wiffle golf balls and cover with a layer of clean plastic pot scrubbers. Pack the rest of the container with quilt batting.

    • 5

      Attach the water intake hose or pipe on your pond pump to the PVC pipe on the outside of the container using a hose, tubing or clamp that came with your pump.

    • 6

      Replace the screened lid and snap the lid on tightly. Submerge the filter in your pond. Allow all of the air to bubble out and then turn on the pump.