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What is biofilm and how to handle it in hydroponics

What is biofilm and how to handle it in hydroponics

Ever since the advent of hydroponic growing systems, the methods of sustainable agriculture have undergone complete revolution. Hydroponic systems can have different media types and everyone has their own favorite. The irrigation system of hydroponics is susceptible to the formation of biofilms. Here is everything you need to know about biofilms and their elimination from hydroponics: 

Biofilm Explained 

Biofilms are not exclusive to hydroponics as you can find them in humans, animals and other plant-based production systems. In simple words, biofilms can be explained as colonies of microorganisms in which the living cells are attached to the surface or each other continuously. It is like they are holding hands as they multiple and spread out and then start to pile up on one another. 

Biofilms in Hydroponic growing systems 

In Agriculture production systems, especially hydroponics, Biofilm appear as a layer of brown or green algae sticking to the internal surface of pipes and tanks in irrigation systems. They are very small in size, less than 20 microns, which is thinner than a human hair,  which is why growers can only observe them as films of brown or orange tint. Another interesting fact is that they love greenhouses and hydroponic organic growing systems where the irrigation water is mostly untreated and contains abundance of organic compounds to aid the growth of heterotrophic microorganisms found in them, some of which can be detrimental to plants and humans. The common Heterotrophic organisms found in biofilms include: 

  • Bacteria species such as coliforms or E. Coli 
  • Other varieties of Dead and living microbes  
  • Secreted compounds such as DNA, proteins, polysaccharides, minerals and lipids 

      Why you should eliminate Biofilms? 

      To put it simply your yields can suffer and underperform! Biofilms are mainly a foe in hydroponic growth systems as they not only deplete the natural nutrients from the water but also have the ability to encourage infections in the lines of hydroponic growth – resulting in plant disease and poor yield. The complexity of the components found in their structure makes their elimination very hard. Even the treated municipal water sources have residual amounts of heterotrophic microorganisms which can cause trouble for growers. Growers face huge yield losses even after the application of organic fertilizers simply because of the stubborn biofilm formation in hydroponic irrigation systems. Other issues include blockages of drippers and narrow pipe work, which can result in the plant being under watered and fertilized.  Pumps can also become blocked and break over time if not cleaned regularly due to biofilm production.   

      How to eliminate/handle biofilms in hydroponics to maximize yield? 

      Biofilms are characterized on the basis of their density in many situations. The density of microbes present in biofilms depends on: 

      • Bacterial level of the water entering the system 
      • Temperature of the water 
      • Nature of the irrigation system pipes  
      • Residence time of water in pipes 
      • Amount of disinfectant residual in pipes 
      • Water flow conditions and availability of nutrients


        We would strongly suggest the application of Hydrogen peroxide to remedy any existing biofilm problems such as those provided by Silver Bullet, which is a silver stabilized version. As a preventative measure we would use silver bullet roots to treat the water regularly to maintain its cleanliness throughout grows. The following methods can also, and have partially been used to eliminate biofilms, but may not necessarily be advised: 

        • Heat pasteurization 
        • Membrane Filtration 
        • UV treatment 
        • Slow Sand Bio filtration 
        • Regulated and specifically designed ozonation systems 
        • Adding safe concentrations of chlorine dioxide or sodium hypochlorite through your system 

            Keep In Mind! 

            Elimination of Biofilms is a continuous and steady process. You must stay patient while killing the microorganism, otherwise, you may end up killing the plants in the process. Remember that Biofilms have a complex nature and unless you have a proper remediation design such as the weekly use of silver bullet mist you may end up doing more harm than good. Silver bullet does not deposits residuals in your plant and actually increases oxygen concentration in the roots which is something I can not guarantee for other methods that are listed online.