You would be very WRONG if you think that you can start planting the seeds in the pots the moment you place the fish in the tanks.
At this stage, your aquaponics system is still lacking the bacteria that are essential in establishing the balanced ecosystem and synergy between the fish and plants.
Why Is There A Need To Get Your System ‘Cycled’?
Without these bacteria, the ammonia-rich fish wastes cannot be broken down and transformed into soluble nutrients (nitrates) that can be absorbed by plants for growth.
Soon, the fish wastes in the tanks will build up to toxic levels and you will see your fish dying. The seedlings are also unable to grow due to the lack of nutrients.
Hence, you will first need to establish the bacterial populations within the aquaponics system so that plant growth and fish life can be supported.
There are a few ways you can get your system cycled:
- Cycling with fingerlings or feeder fish
- Fishless cycling
But first of all, you will need to get a freshwater test kit to monitor the ammonia, nitrite, and nitrate levels as well as pH throughout the cycling process.
This is the only way to know if you need to take corrective action if any of these important elements go out of range and to determine when your system is fully cycled.
Aquaponics How To: Cycling With Fingerlings or Feeder Fish
This is a traditional method to establish your bacteria populations naturally, typically taking at least 1-2 months. You can start up your system by using either the fingerling of your intended fish species or cheap feeder fish such as goldfish.
As the fish in the tanks start producing ammonia-rich wastes, it attracts the air-borne nitrosomonas bacteria to populate the surface of the water. These bacteria will then convert the toxic ammonia into nitrites, which are still toxic to fish.
However, the presence of nitrites will attract the nitrobacter bacteria. The nitrobacter bacteria then convert the nitrites to nitrates, which are harmless to the fish but are essential nutrients for the plants.
IMPORTANT: You will need to keep a close watch on the water quality and the state of health of the fish. At this initial stage of getting your system cycled, toxic ammonia and nitrites are accumulating in the tanks. This can be very stressful to the fish.
TIP: While getting your system cycled, it is best to feed the fish small amounts of food to avoid ammonia spike and algal bloom. Stop feeding your fish if you see an algae bloom or the ammonia/nitrites levels increasing to a high level of 1 ppm as this signals that the bacterial population is insufficient to transform the wastes. Only resume feeding when the ammonia and nitrite levels return to 0.5 ppm and below. You can start increasing the feeding rates after 2 months when a robust bacterial base has been established.
Aquaponics How To: Fishless Cycling
As the name suggests, fishless cycling makes use of other sources of ammonia instead of fish.
Compared to the traditional method of cycling described earlier, it is faster as it allows you to use higher doses of ammonia and control precisely how much ammonia to add without having to worry about the survival of your fish.
Hence, it is probably a less stressful process for the fish and yourself.
Fishless cycling can be accomplished in 10 days and the good news is that you can fully stock up your fish tank once the aquaponics system is fully cycled.
This is unlike the traditional method which requires you to gradually increase the stocking density.
There are again several ways you can add ammonia to the system:
- Pure liquid ammonia: It is relatively inexpensive and can be found in most local hardware or cleaning supply stores. Else, you can also order it online.
- Ammonium chloride: It is available in most aquarium supply stores as a concentrated dry form. However, it will be more costly
Once you have identified the source of ammonia to use, all you need is to follow a simple set of instructions to start the cycling process and monitor the ammonia, nitrites and nitrates levels.
Aquaponics How To: Determine When to Plant The Seeds
The only way you can determine when is the cycling process completed is to monitor the water quality daily with the water test kit.
Cycling is completed when the ammonia and nitrite levels drop to zero and the nitrate levels increase to 5-10 ppm.
Your system is now ready for the fish (if you are using fishless cycling) and you can start planting!
You can speed up the cycling process by ‘seeding’ your system (i.e. adding bacteria) from existing colonies. Sources of bacterial include nitrifying bacteria product found in commercially available cycling kits and disease-free aquarium filters.
Next Step: Find Out More…
Hopefully the above tips and information on system cycling has been useful.
What I suggest you to do now is to visit the Aquaponics 4 You website. It comes jam-packed with step-by-step instructions, explanations, detailed diagrams and even videos to guide you through building and running your own DIY aquaponics system successfully.
You will even receive bonus e-books on organic farming and healthy cooking when you purchase the DIY aquaponics guide!