How to Make a Fish Bowl With Activated Charcoal

Many novice aquarium enthusiasts leave gold fish bowls with no filtration or aeration, performing partial water changes every few days as the only means of cleaning bowl water and gravel. Constantly disrupting the tank takes its toll on fish health and continuously stirs up debris in water. However, under-gravel filtration systems with activated charcoal cartridges provide a better alternative. The activated charcoal removes chlorine, heavy metals and other toxins, keeping water safe for fish and crystal clear. A cousin to the under-gravel filters made for larger tanks, gold fish bowl filters are smaller and circular in shape, a perfect fit for the bottoms of fish bowls.

Things You'll Need

  • Gold fish bowl under-gravel filter
  • Activated charcoal cartridge
  • Aquarium gravel
  • Small aquarium air pump
  • 2 or 3 feet of flexible aquarium airline tubing
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Instructions

    • 1

      Place the filter output tube, a small clear cylinder about 3 or 4 inches long, into the round housing in the filter base before installing the activated charcoal cartridge at the top of the output tube.

    • 2

      Attach the airline tubing to the small peg pointing upright on the top of the filter base. This peg typically is located next to the output tube housing. Attach the other end of the airline tubing to the pet on the small air pump, but do not plug in the pump yet.

    • 3

      Place the filter base inside the fish bowl with the output tube and activated charcoal cartridge pointing upward and positioned in the rear of the bowl.

    • 4

      Add a layer of charcoal atop the filter base about 1 inch deep.

    • 5

      Fill the fish bowl to the desired level, with the water rising at least 1 inch above the top of the activated charcoal cartridge.

    • 6

      Plug in the air pump. Water and air bubbles should begin flowing through the filter and exiting the top of the filter cartridge.

    • 7

      Wait at least a week before adding gold fish to allow beneficial bacteria, an essential to good fish health, to grow in the gravel and filter cartridge.