How to Make an External Aquarium Filter

An aquarium filter removes the excess debris, organic matter, excess food, waste product and free-floating particles to keep the aquarium water clean. This filter either sits inside the tank or outside of the tank. Aquarium owners who choose to use an exterior filter, do so because there is either no room for the filter in the tank or it is not aesthetically pleasing. To cut down on costs you can make your own external aquarium filter and place it in an out-of-the-way area so it is not seen.

Things You'll Need

  • Plastic or silicone canister
  • Drill
  • Silicone sealer
  • Flexible PVC
  • Water pump
  • Water pump hose
  • Knife
  • Lighter
  • Gravel
  • Aquarium filter material
Show More

Instructions

    • 1

      Find a watertight canister or plastic container with a lid that can open and close, but closes airtight. Something similar to a plastic storage container works well. It should be approximately 12 to 16 inches tall by 6 to 12 inches wide.

    • 2

      Mark an area 1 to 2 inches in from the sides of the container top with a pencil. Drill or cut a 1/2- to 3/4-inch hole on each mark.

    • 3

      Cut two 3- to 4-inch pieces of flexible PVC tube. Make sure the diameter of the tube is a size that fits snugly through the holes.

    • 4

      Squeeze silicone around the tube where it enters the hole to seal it and prevent water from seeping through the cracks. Open the lid on the canister and seal the interior holes in the same fashion. Allow the canister to dry for two or three days.

    • 5

      Heat the blade of a knife with a lighter flame or the flame of a gas stove. Insert the knife in the top cover, making small breathing holes in the filter. The hot knife makes cutting the plastic easier.

    • 6

      Attach a pump hose to the intake valve on the pump and insert the other end of the hose into one of the PVC tubes. Feed the hose all the way to the bottom of the canister. Place the end of another pump hose into the other tube on the canister making the out-take hose. Feed it down to the bottom of the canister. Place the other end of the hose in the aquarium.

    • 7

      Open the canister lid and fill the bottom of the canister with fine gravel. Cover the bottom inch of the canister.

    • 8

      Fill the rest of the canister with aquarium filter material. Close the canister, adjust the hoses until they sit just slightly above the gravel.

    • 9

      Place the water pump in the aquarium and connect it to the power outlet. Water should flow through the intake hose into the canister, cleaning it as it moves through the filter material and returns to the aquarium through the out-take hose.