Filter Diagram

Most pond owners either naturally balance their pond with goldfish and plants, or use mechanical filtration. While this may be efficient for a while, this does not address the problem of toxic buildup from fish waste and organic waste, leaves, etc. The answer is biological filtration. Bio-Filters grow colonies of nitrifying bacteria, in the filter medium that consumes waste buildup. This is the same slimy film found naturally in lakes, ponds and rivers. You will need to feed bacteria, (A.B.A., Clear Pond, Aqua Five) into your filter system two to three times before your filter balances. This can take thirty to sixty days. Be patient and watch you water chemistries.

High ammonia and nitrate levels, (by products of fish waste) are toxic to fish. Ammonia and nitrite levels can be reduced by 1/2 water changes and discontinued feeding for a few days.

Nitrite toxicity by salting the pond. The salt should consist of 2 lbs. of salt per 100 gallons of pond water. Leave the salt in the pond. Plants will only take 1.5 pounds per 100 gallons of water.

A few basic concepts: Filter Bed:
The larger the filter the better. Use brushes, filter matting, bio-balls or washed lava rock. I prefer matting.

Pond Volume:
Once through the filter every 2 - 3 hours. Water flow too fast results in insufficient exposure to bacteria.

Oxygen:
Nitrifying bacteria is aerobic and must have oxygen to function or process.

Water enters the filter at the top, into the aeration tower. The water falls down the aeration tower (oxygenating the water) and flows back up (gravity) through the filter medium.

As the water courses through the medium the bacteria processes fish waste and debris. The water reaches the top of the filter and flows back into the pond through the return pipe.

Maintenance: Once a month drain the filter, (bottom drain). Hose off the exposed filter matting with a hose. Do not remove the matting from the filter or you will wash your bacteria colonies away. Hose down the aeration tower until the water runs clear. Shut the drain and restart the pump.

If your pond is heavy with algae you'll need to rinse the filter once a week. The heavy concentration of algae on your matting can suffocate the bacteria and interfere with the colonizing process.

Be patient, the water will clear!