How to Filter a 210 Gallon Freshwater Fish Tank

Filtering freshwater aquariums is vital to the health of your fish and the cleanliness of your tank. There are several types of filtration that you must consider when determining the best way to filter your freshwater tank: mechanical filtration, biological filtration and chemical filtration. The purpose of filtration is to reduce the amount of toxins that build up in the water from fish metabolism and facilitate the breakdown of organic matter such as fish waste, excessive food and algae. Filtration also removes cloudiness caused by floating solid matter and neutralizes harmful compounds introduced into the tank through periodic water changes.

Things You'll Need

  • mechanical filter
  • filter floss
  • water conditioner
  • biological canister filter
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Instructions

    • 1

      Assemble the mechanical filter. Your mechanical filter will come in several pieces and will need to be assembled before using. The first step is to attach the water intake device. This is the hollow tube that will extend into the aquarium and allows water to enter the filter mechanism. It will usually slide directly into the bottom of the filter device.

    • 2

      Insert the filter floss into the mechanical filter. The open cavity at the top of the filter mechanism will be where the aquarium water will pool to be filtered before spilling back into the tank. The filter media will be inserted into this cavity.

    • 3

      Attach the filtering device to the side of the tank. With large filters, this is usually accomplished by hooking the lip of the device over the edge of the tank. Some filters will attach with a suction cup, but this attachment method is usually reserved for smaller filters.

    • 4

      Add the appropriate amount of water condition to remove heavy metals, chlorine and chloramines from the tap water used to fill the tank. This step is known as chemical filtration. Once again, water conditioners can be purchased from any pet supply store and should be used per the directions on the back of the bottle. It is important to condition all water, whether it is from partial or full water changes, that comes into contact with your fish to ensure that they are not exposed to any harmful compounds in the water.

    • 5

      Install a separate biological canister filter per the package directions. As you will probably be changing the filter floss in your mechanical filter somewhat often due to the build up of organic material, biological filtration is important to help grow beneficial bacterial. The canister filter will ensure your bacteria have the proper place to grow and thrive. Beneficial bacteria converts fish waste into harmless compounds and facilitates the breakdown of organic waste.

    • 6

      Speed the biological filtration process along by adding beneficial bacteria cultures to your water and keeping your fish load low. These bacteria also need plenty of oxygen in order to proliferate. Make sure that you are moving the water with mechanical filters and add bubblers to the tank to properly oxygenate the water. This will not only benefit bacterial growth, but the fish will enjoy the added oxygen as well.