How to Build a Filter System to Polish or Remove Suspended Particles in Pond Water

The key to removing suspended particles from pond water is mechanical filtration. There are a number of different ways to build a filter for a pond, but the goal is the same: Send the water through a fine mesh that will capture the particles. Many ponds use a skimmer to remove surface scum, but these are not as effective as removing particles in the water. You need to add an extra filtration device that draws water from under the water line.

Things You'll Need

  • Water pump
  • Mesh screen
  • PVC pipe
  • Plastic container
  • Plastic light diffuser (egg crate)
  • Filter media
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Instructions

    • 1

      Draw your filtration system to scale according to your availability. You will need a pump to draw the water from beneath the water line in the pond and push it into the filter. The filter is simply a plastic container filled with filter mesh to catch the debris. The water will then flow from this filter and return to the pond by gravity.

    • 2

      Add a wide screen to the intake of the pump. The larger the surface area of the screen, the less it will restrict the flow of the pump, which means the pump will not have to work as hard. Also, a larger surface area means water being drawn in with less pressure, which reduces the chances of a fish getting stuck to the screen. You can make a screen out of green plastic garden fencing provided your fish are larger than the openings on the screen.

    • 3

      Plumb the pump so that it pushes the water up out of the pond and into the bottom of the filter container. You will likely need to drill a hole in the bottom or low on the side of the container and use a bulkhead to secure the PVC pipe. You can hide the pipe with plants or dirt so long as you are able to get access to it if needed. Make sure the pipe is at least as wide, if not wider, than the outlet of the pump. Narrower pipe will restrict the flow and strain the pump.

    • 4

      On the inside of the container, plumb the water intake on the bottom so that it splits into two pipes using a "T" joint. If the water comes in from a single area, the filtration will be reduced since the media nearer to that location will quickly clog. By splitting the water into two directions, you will ensure that the water is distributed under the filter media.

    • 5

      Add the egg crate material into the container so that it stands a few inches off of the bottom. You can add things to the container to hold up the plastic egg crate such as stones or jars filled with gravel. Raising it off the bottom will give the water time to swirl around and distribute under the filter media.

    • 6

      Add your filter media to the inside of the container. Fill the container up nearly to the top. You can use a variety of different things as filter media including filter floss, nylon mesh and scrubbing pads (if they are free of soap and detergents). If you use filters with different size meshes, place the finest mesh filters on the top of the container. This will allow the coarser filters to remove the large particles first.

    • 7

      Attach a return line from the container into the pond. Depending on your container, you may have to drill a hole near the top of the container and fit a bulkhead. The return line should be wider than the pipe leading into the container to ensure the container does not overflow. It is a good idea to put a wide screen on the outlet from the container to block any loose filter media from entering the pipe.

    • 8

      Turn on the pump to test the system. The pump should not create a whirlpool in the pond. If it does, you need to submerse the pump deeper in the water or use a smaller pump.