In this episode, Dr. Storey talks about:
- Microbes and why they’re important
- What microbes are doing for you
- How you can foster good microbial communities
- How to spot problems
Microbes are the heart and soul of your aquaponics system. They mediate all processes, from digestion in the gut of the fish, to mineralization of nutrients in the water.
What is the role of microbes in aquaponics?
Microbes oxidize ammonia into nitrite, then again into nitrate. The two most important microbes are (probably) the bacteria nitrobacter and nitrosamonas, but there are thousands and thousands of microbes doing this. I say probably because the world of microbes is so unexplored that there’s no way to be sure with our present knowledge of the microbial world. (Never assume that you know what’s going on with your microbes.)
Microbes also run the mineralization processes. Essentially, this means taking solid waste and breaking it down into plant available nutrients. This can happen at a variety of pH values, at different temperatures, and anaerobically as well as aerobically. It’s an incredibly broad spectrum that we truly cannot grasp. Our insight into the world of microbes is minute and myopic.
How do we foster and maintain a strong microbial community?
This is important to getting a healthy system and reaching system maturity. Typically, this takes about 6 months for the initial settlement, and twelve to eighteen months for full stabilization. What’s happening during this time? The bacteria are moving into the system, finding good colonization areas, and finding food sources. The establishment of bacteria is complete somewhere around 6 months. At this point, the system is colonized but not overcrowded. Over the next year, populations increase, BSA (biological surface area, the area on which microbes can live) becomes less available, and microbial populations begin to compete. Bacteria with different jobs become more or less dominant, and around 12 or 18 months, it starts hitting a nice balance. This is when you start seeing top production at a more constant rate.
Your part in fostering a good bacterial community is just keeping things consistent and giving different species a chance to catch up to each other and strike an equilibrium. Have a consistent management system. Even with fluctuations in management consistency, however, it’s hard to really harm your bacterial community- it will always come back and re-balance itself. The only thing you could do to harm it in the long term is to not provide enough BSA, which directly correlates with the amount of bacteria that your system can house.
This is the top issue you should be concerned about for your system. It is more important than plant to fish ratio, fish to gallon ration, etc. – it is key to a good system. We can’t express how important BSA is! (See more about surface area in this video.)
Other things that help microbial populations are warmer water and a high turn-over rate.
How can you measure microbe health?
Often people mislabel crashes as a microbe problem, when in reality microbes are very resilient and microbe crashes are extremely rare. As Dr. Storey says, figuring out what is a causing a problem takes some detective work. Be wary of blaming the problem on microbes. They will seldom be the culprit.
You cannot over value your microbes. They should be your top priority in your system- above your plants and above your fish.
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