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Why Filter?

A pond is a complete, miniature eco-system. Problems occur if any of its componets get out of balance. Modern filtration systems use a natural, chemical free process to create a healthy balance in the pon, helping to maintain water clarity, and create a healthy environment for fish and pond plants.

Mechanical Filtration:

Mechanical filtration is a system of removing particles, debris and fish waste from a pond (pond pollutants). Layers of sponge or similar material is housed in a filter box, usually located outside of the pond. The pond water is reticulated through the filter by means of a submersible pump, allowing the filter to trap pollutants and return the filtered water to the pond. Water can be returned to the pond via a waterfall, or through a tube. Pond water tends to become brown and discoloured if excessive amounts of pollutants are present.

Pond pollutants are introduced into your pond via the accumulation of solids settling on the bottom.
These solids can be categorised into two broad groups:
1. Fish waste products: eg. Ammonia.
2. Decaying vegetation.

Biological Filtration:

Biological filtration is a method of growing microscopic "good" bacteria in a filter box or container. Colonised bacteria converts the high levels of ammonia present in the pond to harmless nitrogen compounds. Products containing nitrifying bacteria are available to speed up this bacteria process. A filter system must run 24 hours a day to ensure a healthy and effective colony of bacteria exists within the filter.

Pump Selection / Flow Rate:

Pumps should be sized on the basis that the total volume of water passes through the filter approximately every 2 - 3 hours for goldfish, and every 1 - 2 hours for Koi Carp. Pump sizes may be larger depending on whether a waterfall or other water feature is to be run after the filter system.

Aeration:

Air pumps are primarily used to oxygenate the water for fish, however by introducing oxygen into the pond water, your filtration system will work even more efficiently. Air pumps are installed outside the pond above the water level, and air is pumped via flexible tubing to small 'air stones' located under the water. The tiny bubbles released from the air stones benefits the fish and provides the right environment for the production of the biological enzymes.

U.V. Clarifier:

Where ponds are subjected to excess sunlight, large quantities of microscopic algae grow in the water. They create the green water that spoils the pleasure of a pond by making it difficult to see plants and fish. It's important not to confuse 'green water' with the long strands of blanket weed that are also very common. Green water algae are so tiny that ordinary filters cannot trap them. This is where a filter system would benefit from the use of an in-line ultra violet clarifier (UVC).

As the pond water passes through the UVC, the light makes the algae clump together so they are caught in the filter foam or sink to the bottom of the pond.

Common questions:

Do I need a pond filter?
Unless you are keeping very few fish in a very large pond, you are going to need some form of filtration system. If however your primary interest is a water feature with no fish or plants, you may be able to achieve good water quality without a filter, with the use of pond additives (See the DIY Pond Maintenance guides).

Can I turn off my pump at night?
No! Filtration must run 24 hours a day. Night time is the absolute worst time to turn off the pump if you have fish. During the day plants take CO2 from the water and give off oxygen. At night however, the plants steal oxygen out of the water and give off CO2. Aeration is vital to your fish and lack of aeration will kill.

Click HERE to view the Filtration Products List.

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