How to Use a Pond Sand Filter as a Koi Pre-Filter

Filters remove the toxic metabolic waste from koi ponds. The beneficial bacteria strains that convert these toxic products into harmless substances coat the biological filter material that is included in the filter. Over time, slime builds up and smothers these bacteria colonies, which destroys their ability to purify the pond water. A pre-filter, which receives pond water before it reaches the biological filter material, is able to remove detritus and debris from the water and thereby prevent a build up of sludge over the bacterial growths.

Things You'll Need

  • Sand filter
  • 10-gallon plastic bucket
  • Plastic stick
  • Transparent plastic tubing, 1.5-inch diameter
  • GenX -2400 volute submersible pump
  • Submersible pond pump
  • 4 clamps
  • Koi pond filter
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Instructions

    • 1

      Rinse out the sand filter with a garden hose.

    • 2

      Fill a 10-gallon bucket half full with filter sand and place under a garden tap. Turn on the tap fully to agitate the sand and allow sufficient water to run into the bucket. The water should just cover the sand. Turn off the tap and use a plastic stick to stir the sand.

    • 3

      Pour off the dirty water, taking care not to lose any sand in the process. Continue to add and pour off water until the sand is clean.

    • 4

      Add the clean sand to the sand filter.

    • 5

      Fill the bucket half full with a second amount of unwashed sand and continue to clean the sand until you have filled the sand filter.

    • 6

      Replace the top of the sand filter on its body and secure with the clips or nuts provided.

    • 7

      Push one end of a piece of transparent, 1.5-inch diameter plastic tubing onto the exhaust nozzle of your submersible pump and secure it in place with a clamp. Place the pump into your pond and position the pump on a brick or similar raised area to prevent the pump from drawing in the sludge that accumulates on the bottom of ponds.

    • 8

      Push the free end of the transparent plastic tubing over the inlet pipe of the sand filter. Secure the tube in place with a clamp.

    • 9

      Push one end of a second piece of 1.5-inch diameter, transparent plastic tubing onto the outlet pipe of the sand filter and secure with a clamp.

    • 10

      Push the free end of this tubing onto the inlet pipe of the pond filter. Secure the tubing with a clamp.

    • 11

      Connect the submersible pump to a power supply and turn it on.