How to Build and Make a Divider in a Filter for an Aquarium Pond

Dividers, also called baffles, in aquarium and pond filters let you add different filtration media to different sides of the filter. This in turn lets you better control and customize the filtration system to your needs. Some pond filters use the same filtration strategy as aquarium filters: A mesh particulate filter over plastic or ceramic balls (bioballs). Adding a divider allows you to add other filtration such as activated carbon, chemical reactants, such as those that remove phosphates, and sediment filters.

Things You'll Need

  • Sheet of acrylic
  • Saw
  • Aquarium-safe silicone
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Instructions

    • 1

      Measure the area in the filter where you will add the divider. Some filters may not be perfectly square, so measure all four sides on the inside of the filter.

    • 2

      Subtract 1.5 inches from the height of the divider. This extra space will allow the water to flow over or under the filter.

    • 3

      Cut out a piece of acrylic sheeting to fit your measurements. You can use a fine-toothed hand saw or an electric circular saw. Jigsaws risk cracking the acrylic.

    • 4

      Fit the cut acrylic divider in the filter. You may need to trim a few sides to make it fit correctly. Don't worry about small gaps, you will fill these with silicone.

    • 5

      Slide the divider into the filter and cover the sides with a bead of aquarium-safe silicone. If the water will come over the top of the divider, add a bead of silicone to the bottom of the divider as well. Add silicone to both sides of the divider to add strength.

    • 6

      Let the silicone cure according to the instructions for the silicone sealant.

    • 7

      Test the filter to make sure it runs properly. You may need to make adjustments to the divider. If you need to cut it down, you can remove the silicone to pull out the divider, or you can use a high-speed rotary tool to cut pieces off the divider.