Because of the recent events of the last week within my own system, high Nitrates, and Nitrites, I thought it would be prudent to explain what I have learned. First I would like to thank Jason at North Texas Aquaponics for insight into my potential problems. Like the stubborn man I am, I decided to cycle my system with fish, I knew the risk to the fish but thought that with due diligence I would be able to decrease the amount of fatalities caused by Nitrate, and Nitrite spikes. Given I was never, ever going to introduce any foriegn toxins into the system, but maybe some bacteria cultivated some where else i.e. pet store, or a already established aquaponics system. Needless to say i have lost two more catfish. For some reason the Nitrate and Nitrite spikes have not hurt the Bluegill.
There are two ways to first start your system, with fish or without. To cycle your system without fish all you have to do is add your plants and feed them plenty of Seaweed extract. Then you test your water daily, adjust your PH, and wait for the Nitrates and Nitrites to spike, after which you wait until the system is down to tolerable levels for your fish. After this phase you add your fish and continually check your PH,Ammonia and your Nitrites and Nitrates. Spikes within these tests can tell you a lot, I will explain in a later post. To cycle your system with fish all you do is add everything at the same time, your cycle may be shorter, but you need to expect some fish deaths.
The nitrogen cycle consists of Ammonia from fish waste and uneaten food, Nitrobacter, Nitrosomonas and your plants. The process works something like this, first your fish eat, then defecate and urinate, in an aquaponics system that waste, to include uneaten food is then deposited into your grow beds. Once in your grow beds Nitrosomonas convert the harmful Ammonia into another potentially harmful substance, Nitrites. The easiest way to understand how Nitrites are harmful to fish is to use an analogy, Nitrites are to fish as carbon monoxide is to creatures that breath air. High Nitrite levels can lead the fish to die from what is referred to as “Brown Blood”, where the Nitrites attach to the fish’s lungs and gills basically robbing them of the ability to breathe. The Nitrites are then consumed by Nitrobacter which produce nitrates. Nitrates are not typically toxic to fish but they are one of the first signs that your system is out of balance, with the potential of Nitrite levels rising. Nitrates are then utilized by the fish, in turn cleaning the water of Ammonia.
My system is now spiking, so I hope that the Nitrobacter’s get on the ball and hurry to bring the nitrite levels down. I do not plan on using any foreign toxins to artificially bring these levels down, but perhaps I will ask Jason at North Texas Aquaponics to use a few rocks from his system in order to introduce more bacteria into mine. If you have any questions or comments please feel free to leave them. If there is a certain subject you would like to write about feel free to ask as well. I hope you all have a great day, and Happy growing.
A representation of the Nitrogen cycle
Sage Aquaponics 