How to Make an Aerator for a Fish Tank

Since home aquaria are very small bodies of water, most of their residents require supplemental oxygen pumped into the water for survival. Aquarium aerators provide this necessity. Aerators also filter the water remove chemical and biological waste products from the water.
Commercial fish tank aerators can be extremely expensive. But you can quickly make this filtration device with cheap materials. It is important that the PVC pipe is thick enough to fit firmly inside the top of the bottle, and short enough to keep it from extending above the surface of the water. When you go to purchase the PVC, bring the bottle with you.

Things You'll Need

  • Hobby knife or sturdy scissors
  • Fork
  • 7/8 to 1-inch thick PVC pipe
  • Plastic 2-liter bottle
  • White vinegar
  • Uniodized salt
  • Untreated sponge
  • Aquarium silicone
  • Aquarium filter wool
  • Aquarium air tubing
  • Aquarium pump
  • Aquarium charcoal
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Instructions

    • 1

      Pour about a cup of vinegar and ½ cup of unionized salt into an empty 2-liter bottle. These cleaning agents will not harm your fish should you fail to rinse well enough. Cap the bottle and shake it well to remove any residue from the inside of it. Empty the bottle and rinse it thoroughly. Take the label off and discard it.

    • 2

      Use a hobby knife or sturdy scissors to cut the top 4 ½ inches from the bottle. Take off the lid and throw it away. This will become the inner chamber of your aerator. The bottom section of the bottle will be the outer chamber.

    • 3

      Use a heated fork to poke lots of holes near the top of the inner chamber. Create a 1-inch wide band of holes around the bottle right below its neck.

    • 4

      Set the inner chamber inside the outer chamber with the bottle's neck pointing upward. Snug it as far in as you can.

    • 5

      Poke the PVC pipe about 2 inches into the inner chamber's neck. It needs to fit tightly. If it doesn't, you can use aquarium silicone to seal the gap around it. The pipe should be short enough for the top opening to remain submerged under the surface of the water.

    • 6

      Push the air tubing into the top of the PVC pipe far enough for you to see the end of it poke into the clear inner chamber. Secure the tubing in place by poking a piece of sponge around it in the top of the pipe. Attach the other end of the tubing to the air pump.

    • 7

      Fill the outer chamber with charcoal, surrounding the inner chamber with it. Leave about two inches at the top of the outer chamber empty. Firm filter wool on top of the charcoal, leaving about ½-inch of the chamber empty.

    • 8

      Submerge the aerator in the fish tank and allow it to fill with water. Turn on the air pump.