“Cycling” a system is all about establishing beneficial bacteria to convert the ammonia into nitrates for the plants.


The key things to remember when creating a healthy aquaponic system, is to have a robust biological filter. It takes around 4-6 weeks for an aquaponics system to fully cycle and 6 months for it to find it’s optimum levels – once established, it is then extremely easy to maintain.



If you are setting up your ap system for the first time, your system will not be matured, and will not have it’s biological filter established.  The nitrosomona bacteria which breakdown ammonia can take up to 8 weeks to establish. Remember the bacteria are living, aerobic organisms and require oxygen to live and breed. There are three ways to start your system.



This does not involve bicycles. For people keeping fish for the first time, I would not recommend using this method as it can be stressful for both you and your fish. For people wanting to keep carnivorous fish, they are less likely to attack one another if introduced at the same time, so this method is not  recommended for carnivorous fish.


Although it can take much longer, some people prefer to cycle this way, as you are simply letting an aquarium establish itself and you will be buying fish anyway, so you may as well buy  fingerlings (babies) of whichever fish you intend on growing. Feed them sparingly (1tbsp/day per 500l media) for the first two months, then slowly increase feed to all they can eat in 5 minutes. You can then gradually build up your fish stock.



This way eliminates any potential stress felt by your aquaculture. It’s also quick, taking as little as two-weeks to establish.



Aquaponic Life’s preferred method. As you will most likely be needing to buy  fish food anyway (unless you are planning to feed your fish via vermiponics), this is an inexpensive method. It helps you understand how ammonia can quickly build up in tanks, and why it is important that we test for it.

Simply add a pinch of food into your aquaponics system, and as it breaks down, it will release ammonia, which the bacteria feed on. The number of bacteria is limited by the amount of food, and takes time for the bacteria to increase their population in response to a new food source.



By placing a small dead fish or prawn into your set up, you introduce ammonia for the bacteria to feed from. Doing this, you can see why it is a good idea to  monitor fish health, as dead fish will need to be removed immediately, as they cause ammonia spikes.



Urine contains nitrogen, phosphorus and potassium, and helps plants grow. Using urine as a renewable, organic fertilizer has been practised for centuries, and is also a good way to get your system cycling, known as ‘peeponics’ or ‘humonia’.

The longer you leave a container ofurine in a well-ventilated area, the higher the ammonia content will be. This does two things: Kills of e-coli and makes over-dosing less likely. However, this is not essential, so you could put pee directly into the system (Males will probably find this easier).



This is the surest way to make sure your system is pure. This method isn’t one we have tested, because we’ve found the fish food method so efficient, although this method clearly has advantages on a commercial scale. Ammonia is available in crystalline form, usually from aquarium shops. It is also available in a ‘pure’ liquid form, but be careful not to get one with any additives such as soap because soap stuns fish and could kill your bacteria (remember this when washing your hands any time you deal with fish)





  • Temperatures between 25-30°C are optimum for microbes, similarly, temperatures below 18°C will slow down the process – If cycling with tis, ensure they will tolerate these temperatures.
  • pH 7-8 is preferred for bacteria


If you already have a disease-free aquarium/pond:


  •  Simply take the foam out of your filter and squeeze the bacteria out into your aquaopnics water
  • Add some aquarium or pond water into your aquaponics system
  • Add gravel or rocks  from your aquarium
  • Add ornaments from your aquarium