How Fast to Run a Filter Aquarium

Most fish, particularly marine fish, require strong circulation and powerful currents within their aquarium. Aquarium filters have the dual function of removing contaminants from the water and keeping it moving. Depending on the exact species that you house, aquarium turnover times can vary from four to six times per hour for fresh water and marine fish, to as high as 10 to 12 per hour for marine invertebrates. Strong currents will help oxygenate the aquarium and flush old mucus from the bodies of fish.

  1. Recreating Natural Conditions

    • Marine fish and invertebrate animals, such as sea anemones and corals, have evolved in a particularly stable environment and are unable to adapt to changing conditions within an aquarium. Such changes stress the animals and predispose them to disease by weakening their immune systems. Ensuring that water movement in the aquarium is optimal is therefore very important.

    Power Heads

    • You can place these small, internal pumps anywhere in the aquarium by pushing their adhesive suction cups onto the glass pane. Most power heads can be angled to deliver their current in any direction. Streamers, which are power heads that send the water out in a wide and gentle fan shape, are best for corals and other stationary invertebrates, as these are unable to move away from a current.

    Canister Filter

    • These normally large filters stand below or behind the aquarium and deliver water that they have cleaned through a spray bar. This mode of water delivery not only creates currents, but disturbs the water surface and thereby allows for improved gas exchange between the water surface and the atmosphere. Carbon dioxide, which is a toxic metabolic waste produced by fish, is able to escape into the atmosphere and oxygen is able to enter the water.

    Removing Pollution

    • Fish and invertebrates pollute their water with metabolic waste that must be removed. By ensuring optimal water circulation and turnover times, the filter material is able to remove waste which would otherwise break down and pollute the water. Filters normally contain mechanical, chemical and biological filter materials. In all cases, enough water must pass over the different materials for them to perform correctly. Mechanical filters trap large pieces of dirt, while chemical filters bind potentially toxic products to their structure. Beneficial bacteria that colonize the biological material convert toxic waste to less harmful substances.