How to Fill a Carbon Filter

Most aquarium filters use a three stage process for maintaining water quality-mechanical, biological and chemical. Mechanical filtration is the physical removal of debris, usually by straining the water through some sort of filter floss or sponge. Biological filtration involves healthy bacteria colonizing an established tank. Chemical filtration is generally found in the form of activated carbon within the filter housing. Carbon only works for a relatively short time (depending on your tank load), but can easily be replaced rather than buying expensive refill cartridges.

Things You'll Need

  • Bulk activated carbon
  • Scissors
  • Spoon or scoop
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Instructions

    • 1

      Purchase a bulk package of activated carbon from a local fish supply store or online. Look for brands that are low in dust and do not contain an overabundance of tiny ground up particles, which will simply get washed away and wasted.

    • 2

      Turn off the aquarium filter to change the carbon, and remove the old carbon cartridge from the filter housing.

    • 3

      Open the cartridge and carefully dump out as much of the used carbon as possible. Depending on the manufacturer, you may actually have to cut the cartridge fiber open to access the carbon inside. If this is the case, make the cut as close to the top as possible to avoid spilling later on.

    • 4

      Rinse the remaining debris clean, and thoroughly clean the cartridge fiber with hot running water.

    • 5

      Fill the cartridge about halfway with fresh carbon from the bulk package, using a spoon or scoop to avoid spilling. The exact amount of carbon you use will vary, but a good way to judge the amount is to simply fill to the same level as the original cartridges.

    • 6

      Rinse the refilled carbon cartridge in more fresh water to remove any carbon dust.

    • 7

      Replace the fresh carbon cartridge into the filter housing, and turn the filter back on.