Koi & Pond Tip of the Day
September 3rd, 2015
Most pondkeepers know that the best way to ensure clear pond water is with an ultraviolet sterilizer. Some often overlooked factors are what to do when the UV light is not doing the job anymore. Usually, this is a simple as an old lamp. Depending on the brand, UV lamps should generally be replaced about every 12-15 months of use.
Pond Ecology and Matala® Filter Media
Within the last five years, the water garden and koi pond hobby has seen some major advances in understanding of system designs and pond ecology. This evolution of understanding has progressed from an era based on simple techniques and filter systems and has evolved to the current "high tech" era based on gadgets and accessories.
Sorting through this progressive development we have advanced even further by putting both of these eras into perspective, extracting the best of both worlds. This article is given to increase the general understanding of pond system ecology and to introduce the new filter media known as Matala.
Water Stability vs. Water Quality.
A swimming pool owner wants to achieve filtration that guarantees clean and nearly sterilized water.
A pond keeper’s goal must be to create "Clean, healthy, living water". This can only be achieved in a pond ecosystem where water stability is equally important as water quality. Living water is actually full of microorganisms of all types that forma basic food chain, which in essence create the type of healthy water where our koi and goldfish thrive.
Most of us are informed or aware of the "Pond chemistry" and try to be the alchemist that controls typical water quality parameters like oxygen saturation, ammonia and nitrite levels, pH and alkalinity, dissolved and solid waste levels and of course, temperature.
These "Parameters" simultaneously constitute the nutrients and living conditions of many microorganisms that influence the ponds’ ecosystem. A dynamic and balanced ecosystem is created when these ingredients are kept at stable levels where the microorganisms, algae, plants and fish can find a synergistic state of homeostasis. Synergy is the interaction of the water’s chemistry and all organism’s lives working together. Homeostasis is the movement of these organisms within their chemical world towards an equilibrium where they are healthy. All ponds want to find a balance. Ponds that are stable usually create water of good quality. What the pond owner provides or not will determine how soon and to what degree this balance is achieved.
Stable Filter Systems
Why do some filters work and others you have to do all the work?
Basically, proper size filter tanks and type of media with regards to flow rate, fish density and cleaning routine are the tools that can help you to create pond stability. Simply put, ponds with inadequate filter systems tend to require "disruptive cleaning".
The process or the frequency of cleaning disrupts the ponds stability. Some filters use a lot of water to clean them properly. Big water changes adversely affect the pond micro-ecology and the fish themselves. Some filters require aggressive or frequent cleaning.
This disrupts the stability of bacteria populations. Small filters will not sufficiently contribute to good pond ecology. The pond will be greatly limited by the number of fish you can keep. Plants or algae will have to be the dominant consumer of fish waste. Improper filter systems will require large ultraviolet sterilizers, ozone or chemicals to control algae in koi ponds. A good biofilter is very large and takes months to become fully established.
Many diverse species of microorganisms exist in a truly balanced biofilter, not just nitrifying bacteria. Did you know that the very act of cleaning your filter potentially releases sludge, enzymes, bacteria and noxious gases back onto the fish? Certain medias clog quickly and require "disruptive cleaning" to work at all. Stability is not established when your pond bounces between clean and dirty, clean and dirty. Water gardens and ponds with gravel in the bottom tend to require disruptive cleaning if you want to keep koi. A proper pond design coupled with a good filter and media will promote consistent easy maintenance and drastically reduce this list of potential problems. A good filter system and media promote pond stability.
Matala® Filter Media
Over the course of time hobbyists have tried an endless variety of medias to use in pond filters. Actually, many of them work quite well. Each filter media has distinct advantages and disadvantages.
Usually the best approach is to use various medias to complement each other's weakness. Gravel is a good biofilter and can extract solid waste but it can be difficult to clean and much of the volume of the media is dead unused space within the rock itself.
Filter brushes are denser close to the wires than at the outside. They can remove solids but if installed properly, without leaving open channels, these can be expensive and may leave a little lacking in biofiltration.
Open cell foam certainly has a tremendous surface area for biological growth but tends to plug and becomes anaerobic very quickly. Japanese matting has good biological qualities but it also tends to plug up and does not let go of solids easily. Lately we have seen medias like Japanese matting and open cell foam that is placed in a chamber with open passage ways or holes through the media. This is done to prevent solids from plugging the media. However, we end up with less filter media in the tank and less actual flow through the media.
This open "honey comb" design works well on gravity fed systems where all the solids have settled out first or on systems where a prefilter has extracted the solids. When solids are trapped within the bio-media we are forced to aggressively wash it and thus lose the established balance of microorganisms.
There is no one perfect filter media. Each media will also require certain filter tank accomodations in order to work properly. Like the computer industry we are always looking for better and faster ways to manage our ponds.
First, a little history on Matala filter mats. Marc Talloen is an aquaculturist for over 25 years. He has grown food fish including carp and tilapia in Africa, Europe and Asia. His extensive knowledge of fish culture took him around the world consulting for various aquaculture companies. He eventually laid his eyes on nishikigoi and that was it, he fell in love. He opened his own Koi business in Belgium over 15 years ago. He searched a long time to find specialized filter media that could help solve many of the problems associated with other materials.
Being the energetic optimistic type he set forth to develop Matala. Matala is the first media which is actually made for the express purpose of filtering koi ponds. Matala had to have certain characteristics to give him the desired results. First of all it had to handle the high solid waste levels associated with koi. It had to be easy to clean. The media would also act as a substrate for biological filtering, a home for the good bacteria. A high surface area per cubic foot is necessary. However, the media could not plug up too quickly or the bacteria would go anaerobic. The media would have to provide good movement of highly oxygenated water throughout the entire filter in order to be efficient.
Furthermore, a good biofilter media requires what is called interstitial spaces. These are the small open spaces in between the media where bacteria can "fill up" in a safe and slimy bacterial matrix. Bacteria love interstitial spaces. The perfect media would let go of the dirt during cleaning but sustain the bacteria attached. He realized that many of these requirements are contradictory to one another. Marc, knew that water will always travel the path of least resistance; so his media would have to be positioned in a filter so the water does not go around it. This would require a somewhat rigid type material in order to be wedged in place. He found that another benefit to being rigid was that the media could be self supporting. Always thinking, he concluded that the material would actually be easier to work with if it had a very slight bouyancy. This way it would not end up at the bottom of the filter tank. After many trials and sleepless nights he came up with a series of 4 filter pads with progressive densities which could be used separately or together to complement one another. He gave them different colors so they would be easy to differentiate. Each pad has it’s own unique structure lending itself to a different job in filtration.