Developed by Professor Halvard Odergard at Trondheim University of Science & Technology, Norway, the Kaldnes K1 Moving Bed bio film process has been designed specifically to create the most effective environment for the nitrification process to take place.
The media is engineered in a wheel shape and is slightly positively buoyant. This allows a small amount of water flow to circulate the media throughout the vessel. This flow is created by pumping air through a
perforated plastic circular tube (which is provided), at the base of the Nexus.
How it Works:
Maturing the K1 Kaldnes bio-media is important because a delicate ecosystem is naturally developing for the bacteria involved in the nitrification process. Fish are required to generate the waste which bacteria survive on. The bacteria colonise the new media without the need for additional chemicals. When established, your Kaldnes should be brown in colour.
Oxygen and food (fish waste) give the beneficial bacteria the means to grow, whilst the Kaldnes media provides maximum active surface area for the bacteria to colonise more than other types of static media. It is this process which removes harmful ammonia and nitrite from the water. As the Kaldnes media chaotically circulates within the Nexus Koi Filter, it causes old dead bacteria on the outside to be removed, making space for new
younger heavier feeding bacteria to colonise. Within the wheel is a protected surface, which enables colonies of bacteria to naturally follow their life cycle, maturing and dying, in turn fuelling the latter stages of the nitrification process. It also assists in the breakdown of any small particles passing through from the mechanical stage. Therefore, the K1 Kaldnes media provides a correct mix of both young and mature beneficial colonies, providing a more consistent filter performance whilst improving water quality, encouraging healthier fish and aiding in the reduction of green water and blanket weed.
The maturing process needs monitoring closely to ensure that levels of pH, ammonia and nitrite are within acceptable parameters for your fish. Usually, after a period of between 6-20 weeks the beneficial bacteria will have colonised the media to a satisfactory level to deal with the waste produced by your fish. This period may extend depending on local water conditions, temperature and stocking density.
Due to chaotic movement of the Kaldnes K1 media, the process is self-cleaning and requires no maintenance. This allows the filter to reach optimum effectiveness without the disturbance of periodic maintenance, avoiding unnecessary loss of bacteria within the filter. This prevents high levels of ammonia and nitrite within the water.
Levels of Kaldnes K1 within the Nexus:
Kaldnes K1 has been proven in fish farming with feed rates up to 0.75kgs of 40% protein food per 50 litres of media per day. Evolution Aqua is rating it at a maximum of 0.25kgs of food per 50 litres used, in order to ensure the best possible water parameters are achieved. If a higher feed rate is required, extra media can easily be added. Koi are typically fed at between 1% - 2% of body weight per day. Therefore, for every 5 grams of food fed, 1 1itre of K1 media is required. At Evolution Aqua, our filter designs are based on the higher rate of 2% per day. Below is a table you can use as a guide if you do not wish to weigh your
fish. It Illustrates an approximate relationship between average length and average weight of Koi. (NB: All Koi develop different body shapes according to breed, feed rate, pond design and water current).
Since the development of the Kaldnes Moving Bed process and its successful introduction into the waste water treatment industry in 1991, Kaldnes K1 media has become the industry standard throughout the world. However Kaldnes have not been idle and they have continued their extensive Research and Development programme to further improve the efficiency of their process over the last 12 years.
The Bio Chip is the result of this programme and is much more than just a different shaped media. Although the total protected surface area is more than 2.4 times higher than K1 - this is only part of the story.
The main difference to K1/K3 is that the protected area or quiet zone in Bio Chip, is designed to be the perfect environment for micro animals, not just bacteria. The extremely quiet zones created by the hydrophilic layer protecting every cavity in the Bio Chip, is critical to allow these micro animals to flourish. With other types of media they will be flushed out.
These micro animals feed on small particles such as, fish waste, dead bacteria and algae. There are many different types of these micro animals as you can see from our illustrations. Consider that the Vortecilia as filtering 10,000 times their own volume per hour and are feeding on particles up to 5 microns in size. It is these small particles that are always difficult to remove by mechanical means and make our water cloudy !
Once fully colonised the bio chip contains an army of these micro animals, all filtering tens of thousands of times their own volume every hour, searching for these tiny particles. Gleaming healthy water, high in oxygen content with low BOD (Biological Oxygen Demand) will follow!