What Type of Equipment Is Needed to Set Up an Undergravel Fish Tank Filter?

Undergravel filters are common fish-tank filters. They are popular because they provide at least two of the three types of aquarium filtration: biological and mechanical. Some designs even feature carbon inserts that add the third type of filtration: chemical. Additionally, they are cheaper filters, in the price range of most fish keepers. However, a few additional supplies are required to run and maintain undergravel filters.

  1. All Filters

    • All undergravel filters require certain key components to operate. These include a filter plate, lift tubes and gravel. The lift tubes are required to attach the plate to the source of water movement. If you are using an air pump, you will need at least two lift tubes. If you are using a powerhead, you will only use one. Also, pea-sized gravel is the best size for an undergravel filter.

    Air Pump

    • If you are using an external air pump, certain accessories are required. Airline tubing is required. Silicone tubing works best, as the older plastic tubing tends to become brittle and yellow with age. A check-valve is also a good investment as it prevents water from back-siphoning into the pump if there is a power failure. Lastly, air stones are required to break up the air stream. A splitter valve is necessary if your pump only has one outlet.

    Powerheads

    • Powerheads are a type of pump that goes inside the aquarium. These create more water moment than air pumps. They sometimes require an adapter for attachment to the lift tubes. They are rated by Gallons Per Hour (GPH). Be sure and get a powerhead that can handle at least three to five times the volume of the tank per hour. So if you have a 10-gallon aquarium, get a powerhead that can pump 30 to 50 GPH.

    Maintenance

    • Since undergravel filters use the gravel as the filter medium, they require regular maintenance of the gravel. The best way to do this is with a gravel vacuum, a large-mouthed siphon and a five-gallon bucket. Additionally, be sure to add water conditioners to the new water. In a crowded tank, change 25 to 50 percent of the water every week; in a more sparsely-packed tank, change the same amount of water every other week.