Kaldnes K1 & K3


Kaldnes Moving Bed process, which has been scientifically tried and tested in fish farming and waste water treatment for over 10 years, is now available for fish keepers and is exclusively distributed worldwide by Evolution Aqua.

The media is engineered in a wheel shape and is slightly positively bouyant. This allows a small amount of water flow to circulate the media throughout the vessel. This flow is created with your air pump and air stones or diffuser etc.

How it Works

Maturing the Kaldnes bio-media is important because a delicate eco-system is naturally developing for the bacteria involved in the nitrification process. Kaldnes media provides the 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.

How it is different to other media

As the Kaldnes media moves within the filter, it causes the old dead bacteria on the outside to be displaced. This makes space for new younger heavier feeding bacteria to rapidly colonise. Within the wheel is a protected surface which enables colonies of bacteria to naturally follow their lifecycle, of maturing, dying and then fueling the latter stages of the nitrification cycle. Kaldnes has been designed to provide the best possible habitat for both young and mature beneficial bacterial colonies.

What is meant by 'self cleaning'?

Unlike foam, matting, or other forms of static filtration media, the Kaldnes K1/K3 media is designed to move freely within your filter. The constant chaotic movement of the air from your pump, causes the media to self clean and thus requires no maintenance. This allows the filter to reach optimum effectiveness without the disturbance of periodic cleaning, avoiding unnecessary loss of bacteria within the filter. 50 Litres of K1 media will handle up to 250 grammes of food per day and for K3, 225 grammes of food per day. For retrofit of existing filters, K3 media is the most suitable due to its larger size and ease of control.

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Kaldnes K1 25 Liter
Kaldnes K3 50 Liter
Kaldnes K1 50 Liter


Bio Chips

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 that will colonize the media. Consider that Vortecilia are 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!

Bio Chip 25 Liter