Koi Keeping and Husbandry

How to Keep Your Pond Fish from Suffocating!Excessive green pond algae, leading to algae blooms are exactly what the doctor did not order! Maintaining crystal clear, green free pond water is what is needed to prevent fish fatalities due to oxygen starvation. The only permanent solution is to use a UV sterilizer or UV clarifier on an ongoing basis.

An Ultraviolet pond sterilizer or ultraviolet pond clarifier will guarantee planktonic algae free pond water, providing it is correctly specified for the size of your pond and the UV lamp is replaced at least once a year; usually after 8,000 hours of constant use. After this period of time the level of UVC rays emitted will no longer control the green pond algae floating around within the pond water.

The quartz tube should also be cleaned annually, to remove debris and other matter that has accumulated. A low strength acid that has been diluted should be used. HINT! Soak the quartz tube in a bowl of vinegar, for 2 to 3 hours, as acetic acid contained in vinegar is good enough and low cost!

I would recommend that you run the UV sterilizer or UV clarifier constantly, without switching it off. Some pond keepers switch their UV unit off at night time. In reality it is at night that carbon dioxide levels are at their highest because the unicellular floating algae cells have stopped photosynthesizing, which produces oxygen and have started to respire, which produces carbon dioxide and uses up oxygen. As the level of carbon dioxide rises, the potential for Koi, goldfish and other fish to suffocate rises. Always run your ultraviolet system constantly.

If the UV pond sterilizer runs 24/7 and your pond water has started to turn green anyway then either the UV system is not powerful enough for the size of your pond or there has been a build up of pond salts or other matter on the quartz tube. Any build up on the quartz sleeve will minimize the effectiveness of the UVC rays from passing through the quartz into the pond water.

How to Reduce the Chances of Algae Bloom Developing

* The addition of aquatic plants will not only add a touch of nature to your garden fish pond but will also compete with green pond algae for the available nutrients (nitrate and phosphorous). Pond plants are also an excellent source of oxygen.

* Avoid over stocking your pond with too many Koi and other fish species. The more fish there are in your pond the higher the amount of liquid and solid waste, which in turn results in higher levels of nutrients in the water, along with fish disease causing heterotrophic bacteria. Keep a few fish and do not overfeed as overfeeding also results in higher levels of waste entering into the delicate ecosystem that is your pond.

* Change 10% of your pond water on a weekly basis; this will help to reduce the build up of nutrients. Ensure that you use chlorine free pond water.

* The addition of a floating pond skimmer to your pond will remove organic floating debris, such as leaves, grass, twigs and pollen before it has a chance to fall to the pond floor and decay. Decaying organic matter produces ammonia and carbon dioxide. In addition the removal of pollen and silt will prevent cloudy or hazy pond water.

Remember that floating green algae is easily controlled by ultraviolet light but blanket weed and other filamentous string algae varieties are not. In fact blanket weed will benefit from the lack of floating algae as blanket weed grows best in clear pond water that is nutrient rich. A commonly used solution to filamentous string algae is barley straw. The natural chemicals released by barley straw as it decomposes hinder the growth of string algae species.