How Does A Biofilter Work

How Does A Biofilter Work, Ensuring a thriving Koi fish pond relies heavily on the effectiveness of your biofiltration system. It’s crucial to assess whether the biological filtration in your pond is operating optimally before introducing any fish.

This not only keeps your Koi fish healthy but also allows you to enjoy their presence day after day. Let’s delve into what transpires within a biofilter.

How Does a Biofilter Work?

At the core of the filtration process lies the nitrogen cycle, where ammonia produced by the fish’s urine and excrement is converted into non-toxic nitrates. This pivotal process hinges on the establishment of beneficial bacteria within your pond’s filtration system, which plays a crucial role in transforming toxic ammonia.

The cycle commences when fish consume food, which then passes through their digestive system and is eventually excreted.

Ammonia is a primary toxic compound found in fish excrement. Additionally, excess food and other organic matter, such as leaves, can generate ammonia when they begin to decompose.

So, what exactly occurs inside a biofilter?

  1. High-Ammonia Water Enters the Biofilter:
    Water laden with ammonia enters the biofilter. Within the biological filter media, a group of bacteria known as Nitrosomonas takes centre stage. These bacteria consume the ammonia and convert it into nitrite. Since both ammonia and nitrite are harmful to fish, swift removal from the water is essential. This is why maintaining a high turnover rate is crucial. In the case of Koi fish ponds, it’s ideal to circulate the entire water volume once every hour.
  2. Water with Nitrate Content Progresses to the Next Chamber:
    In the subsequent chamber, another type of bacteria, Nitrobacter, residing in the filter media, consumes the nitrite and releases nitrate. Nitrate, unlike its predecessors, is not harmful to fish; in fact, it serves as an excellent fertilizer for aquatic plants.
  3. The Cycle Repeats Itself:
    This entire cycle repeats continuously once it is set in motion.
How Does A Biofilter Work

The Nitrogen Cycle, often referred to as “cycling,” is a critical process when establishing your pond. When embarking on this journey, begin with a modest number of fish to allow time for the beneficial bacteria to establish colonies. Typically, this process takes anywhere from 4 to 6 weeks.

Regularly monitor the pond’s ammonia and pH levels using readily available test kits. If you have trouble finding suitable kits, we can provide them.

When your filtration system is correctly cycled, you should register zero ammonia and nitrite levels, with nitrate readings falling within the 10-35 ppm range. This is a positive sign of a healthy environment.

Given that your Koi pond operates as a closed recirculation system, any malfunction in the filtration system can elevate stress levels in your Koi fish, which may not be immediately apparent. If left unaddressed, it can lead to severe internal organ damage and, ultimately, the loss of your beloved Koi.

Creating biofiltration systems tailored to your Koi pond is our speciality. Feel free to connect with us for more information on optimizing your pond’s health and the well-being of your cherished Koi fish.