What is it and how does it work?
Bakki Showers allow water to flow into the tier through a spill or spray bar and fall at its own rate through biological filter media. As the water flows through the media, it is exposed to free-moving air, which keeps the oxygenation of the tank water very high. Bakki Showers also creates a very oxygen-rich environment for the bacteria providing biological filtration, which increases their effectiveness. The most efficient filtration system today is the Bakki Shower design.
As an approach, I would divide all filtration systems into two groups: Long term designs and shorts term designs. Short term designs: Is a filter that will work efficiently for a short period of time and gradually the performance will begin to fail off. The traditional sand or swimming pool filter also known as gravel filled chamber filter best illustrates this design. In both designs, channeling and anaerobic activity become more and more likely over time. Low oxygen levels usually go hand-in-hand with this system and it has been demonstrated that only the top few inches can support aerobic (oxygen loving) bacteria, regardless of overall media depth. The other disadvantage of the sand or gravel filter is the amount of water wasted during cleaning or backwash intervals that can be up to twice a week, depending on the stock rate in your pond as well as the filter system design you use. Other examples of short-term designs are reverse flow chamber filters, biobrush systems, submerged bioball and canister style systems.
Long term designs: The group I referred to as long term filter designs would include any system which can remain debris free and oxygen rich indefinitely and employ in its design superior surface area for aerobic bacteria to grow. The leading designs currently available in South Africa are the Bakki Shower and the Vortex Filter that falls into the group of long-term filters.
To appreciate these filter designs; we must first understand the problem how to maintain a large number of koi in a relatively small body of water. Some facts on keeping Koi ….
· It takes 2.2 grams of oxygen to break down one gram of ammonia,
· Koi produce a lot of ammonia, for example: 35 Koi 25 cm in length will produce a 1000 milligrams of ammonia per day,
· Any trapped debris will decay and reduce the O2 in the water,
· Koi will reduce the O2 in the water through normal respiration.
The Bakki Shower Filter is designed to convert ammonia to nitrate by incorporating an oxygen rich environment and a very large surface area for aerobic bacteria to perform their task of braking down. Water enters the top of the Bakki Shower Filter through a spray bar. The spray bar distributes the water evenly over the plastic media from the top tier or bakki to the bottom, working on gravity. A typical Bakki Shower will consist of three to four tiers, working on gravity. As the water cascades over the media, two events occur during this process. First, this action allows gasses, such as carbon dioxide to escape and aids in keeping the pH high. Secondly, by trickling water over the filter media contact between bacteria and ammonium is maximized. During this trickling process, fresh air is moving through the filter media insuring constant high oxygen levels in all areas of the filter media. As a bonus the water trickling through the media has a secondary cleaning and rinsing effect on the plastic filter media by washing away any hits of debris and also any dead bacteria into the sump of the Bakki Shower.
A Bakki Shower probably offers the largest surface area of all filters available on the market in South Africa today. The Bakki Showers also offers the perfect oxygen rich environment for bacteria to grow on. The size of the living aerobic bacteria colony will adjust to its food supply and also the O2 level in the filter. We do not want to restrict the surface area in any way since we have more than enough oxygen in the Bakki Shower and the Koi will certainly supply the food for the bacteria.
The square meter surface area of a Bakki Shower or for that matter on any biological filter depends strongly on the type of media used, also the volume or amount used. On the Bakki Shower the actual size of the filter measures 700mm in diameter and 1,6 meters in height on a four tier unit, but by using the correct filter media inside the filter the square meter surface area can be increased to 300 000 LITERS of water. Obvious it will not always be possible because you would not get the amount of flow through a single four tier filter to clean 300 000 liters of water. Filter will handle up to 500 liters per minute flow and a 300 000 liter pond need 5 000 liters per minute.