What is Kaldnes Media?
Background History of Kaldnes Media
Kaldnes Media was designed and developed in Norway by the combined efforts of education, government and private sectors: the Norwegian University of Science (NTNU), the Foundation for Scientific and Industrial Research (SINTEF), and Kaldnes, a Norwegian industrial company.
This new sewage treatment was intended only for municipal use, but other industries, such as aquaculture, quickly adopted the media and the process, now called the Kaldnes Moving Bed (KMB).
How Does Kaldnes Work?
| K1 Kaldnes Media |
Kaldnes vs. Traditional Ceramic Media
Ceramic media are the most common bio filter media used by aquarists. It looks similar to porous gravel or small pieces of lava rock. Kaldnes media is superior in a couple of important ways.
Kaldnes Media is:
- Light with a density slightly lower than water so that it is buoyant. Ceramic media is heavy and dense by comparison.
- A moving bed filter whereas ceramic media does not move once placed in a filter.
- Self-cleaning. Ceramic media needs to be cleaned regularly (although most aquarists don't).
Kaldnes media is used in a reactor which provides aeration and agitation. This mechanical movement of the media is the key to it's superior nitrifying ability (to break down ammonia to nitrite and then finally to nitrate). As the media moves in the reactor, it bumps into the reactor walls and other media, sloughing off excess biofilm, keeping the media clean so that nitrifying bacteria work at it's peak efficiency. Since ceramic does not move, the biofilm that covers the media gets clogged by "sludge" which is dead nitrifying bacteria and fish waste. Also, the tank water does not flow easily throughout ceramic media thus is far less efficient than Kaldnes media.
Constructing A Kaldnes Reactor
Step One: Materials and Tools
- Empty water bottle
- Kaldnes media. I purchased mine from eBay for $5.99 including shipping.
- Silicone airline tubing purchased at eBay for $5.99 for 50' including shipping.
- Check valves from Amazon for $5.13 (for 5) including shipping. Como plastic check valves
- Airstones from eBay for $2.89 (for 3) including shipping.
- Air pump can be purchased at Amazon for under $10 with free shipping. Tom mini air pump.
- 1 3/4" side-drilled suction cups from eBay for under $10 (for 6)
- Zip ties can be purchased at Home Depot or any hardware store
Tools
- Power drill or a very sharp awl
- Pencil or chopstick
| Materials and tools to make Kaldnes Media Filter |
| Check valve prevents floods during power failures |
| Side-drilled suction cup |
Making openings in the water bottle
Use the drill to make starter holes in the water bottle lid and on the top and bottom of the bottle. Please refer to the video at the end of this blog. Use the pencil or chopstick to gently increase the size of the holes, careful not to damage the bottle.
| Make a hole in the water bottle lid |
| Insert airline tubing into bottle lid hole |
| Airstone attached to airline tubing |
| Air stone inserted into bottle |
|
| Finished Kaldnes Media Filter - 3 hours later |
Kaldnes Media Filter in Action, 24 hours later
Full Video Instructions
The video below is a tutorial that provides real-time instructions on building the Kaldnes media filter.
More Reading:
| My Quarantine Process For New Aquarium Fish | Aquarium Water Change System | Albino Bristlenose Pleco Eggs and Babies |
AquariumForum.com: DIY Forum
Fishlore.com: Freshwater Tanks and Equipment
AquariumAdvice.com: DIY Forum
Kaldnes Media for Biological Filtration
Kaldnes Moving Bed (KMB) Natrix Process
The Influence of Carrier Size and Shape in the Moving Bed Biofilm Process
