What is actually meant by a clean fish pond? Would you assume that sparkling, clear pond water is a sure sign of a healthy, clean pond environment? In actuality this could not be further from the truth. It does not necessarily mean that ammonia and nitrite levels within the pond are under control. Lurking below the surface is a potential disaster waiting to happen. It is critically important to remove chemical impurities, to obtain clean, purified pond water.
Garden pond filters break down toxic ammonia and nitrite into nitrate, a source of fertilizer for aquatic plants, under the influence of oxygen. Crystal clear pond water does not necessarily mean that the water quality is safe for fish and other aquatic life to live in. Adversely slightly murky, green ponds may not look healthy but providing the ammonia and nitrite levels are under control will be perfectly safe for your Koi and goldfish. In fact Koi and goldfish prefer a pond with some algae; they nibble on it, it provides shade from the sun and protection from predators.
Be wary of salesman advising that big filters are for big ponds and small filters are for small ponds. This is not always the case. The key to any successful biofilter is the choice of pond filter media. It is perfectly feasible for a small well matured filter with a high surface area biomedia, containing a large colony of nitrifying bacteria to be more effective than a larger filter using an inferior pond filter media. If you have a small to medium sized pond choose a Fishmate pressurized filter, as this product ships with the excellent Supra bio media as standard. Supra, known as Alfagrog in the UK has a large surface area on which nitrifying bacteria can live and subsequently encourages larges colonies of these bacteria to form, making for effective biofiltration. For large Koi ponds a bead filter is your best bet in the USA. They have been specifically designed to handle the large volumes of water, chemical impurities and solids found in Koi ponds. The Aqua Ultima range by Aqua Ultraviolet is the best selling bead filter range.
Life Is Life and a Filter is A Filter Right?
Wrong! A rather silly sounding statement I agree. I had to try to get your attention somehow! The point I am getting at is that not all filters are suitable for use in a water garden or fish pond. Take a swimming pool filter for example; this is normally a sand filter, which does an excellent job of keeping your swimming pool water crystal clear and clean. Sand filters are actually extremely bad for garden ponds, as they encourage unwanted heterotrophic bacteria to develop, with potentially catastrophic results for the pond water quality and fish population.
The swimming pool filter removes particulate matter found floating in the pool. The water looks clear and shiny. Any bacterial organisms are destroyed by adding chlorine to the water, making for a safe pool in which to swim. If only it was that simple in a fish pond. If you were to add high doses of chlorine to your pond you would soon kill off the fish population.
What Happens To Pond Water As Fish Eat?
Fish need to eat in order to grow and develop. As they eat, they excrete solid and liquid waste into the pond water. This along with any uneaten fish food and organic matter such as leaves, if not removed from the pond, will sink to the pond floor and start to rot, producing ammonia. This situation makes for an excellent heterotrophic bacteria ridden environment with high ammonia and nitrite levels. If the bacteria do not kill your fish, the ammonia eventually will! This is where your biological pond filter starts to earn its money. It successfully removes these pollutants from the pond, leaving you with clean, purified pond water.
Always make sure that you provide a constant supply of oxygen to the biofilter media via a reliable, energy efficient pond pump. Remember that a pond pump needs to supply much needed oxygen to the nitrifying bacteria colonies 24/7. Without oxygen for between 5 to 6 hours the colony will die off. For this reason you should never switch off your pond pump for more than a couple of hours while you carry out routine pond maintenance work.
If your aim is to achieve purified pond water and a pond free from organic debris such as leaves, pollen, twigs and other debris then a pond skimmer is a great idea. For the vast majority of small to medium sized ponds, a floating pond skimmer is your best bet. A floating skimmer, skims the surface of the pond, sucking up any debris, trapping it in a filter basket, which can be easily emptied. This is a great way to remove micro particles such as pollen and silt that would otherwise cause the pond water to appear cloudy.
An occupational hazard for the vast majority of pond keepers, particularly those living in warmer climates, with more sunshine hours is the dreaded algae bloom. This is caused by high levels of nitrogen in the pond, in the form of nitrate, produced by the result of ammonia and nitrite being broken down by your pond filter. The algae bloom multiplies rapidly, turning your pond into a murky green hole. The algae will not only stop your pond water from appearing clean and preventing you from seeing your fish but will also starve the pond of oxygen.
The best way to prevent algae blooms from developing is to use a UV sterilizer. Avoid pond algaecide chemicals as they provide a short term fix, interfere with nitrifying bacteria colonies and if the dosage is too high can make your fish ill or even cause fatalities.
