Aquaponics Explained….a brief summary:
The above illustration is a simple explanation for how the system works. While Aquaponics is actually very complex with many facets, hopefully this will give you a foundational understanding. The water from the fish tank is pumped into a grow bed that contains gravel or hydroton (clay pebbles). The grow bed acts as a Bio-Filter that converts the Ammonia fish waste into a Nitrate food that the plants can use. The low current draw water pump runs 24 hours a day and when the grow bed is filled up, a specially designed Auto Siphon triggers the bed to quickly drain. In this way, the bed fills about every 45 minutes and as the water drains it pulls oxygen into the bed & roots of the plants. Earth worms are also a vital part of the grow bed, they breakdown & transform large waste particles into the most fantastic plant food imaginable!
While there are many variables and considerations required to design a proper system, you can rest assured our Endless Food System kits are engineered for maximum performance. Years of testing, research and hands on experience has enabled us to offer to you a perfectly sized & balanced kit with an easy to follow guide on how to maintain your own high production system.
Moving on from the simple explanation of what aquaponics is, let’s get into a little more detail for those interested in such things. Keep in mind, although more in-depth, the below information is still a summary of sorts as books can, and have, been written about aquaponics (including our own DIY Manual).
What Is Aquaponics – More Details
Specifics of Aquaponics
Aquaponics or the idea of using fish to produce nutrient waste is certainly not a new idea. Several thousand years ago in South China and Thailand they began doing this in their rice fields. Later, the Aztecs used a form of it in their Chinampa canals. For modern history, and the smaller backyard systems, Dr James Rakocy is recognized as the father of Aquaponics for his work since the 1980’s. Other pioneers in the industry include Murray Hallam of Australia, Nelson & Pade of Montello WI, friendlyaquaponics.com, and Sylvia Bernstein of The Aquaponic Source.com.
An Aquaponics system employs many many types of bacteria but we will discuss the major applications here. The fish waste produced is ammonia. In a backyard system it is best to keep the parts per million, ppm, below 6. If it exceeds this level it could kill your fish. The ammonia is broken down by a naturally occuring bacteria called Nitrites. If the Nitrite level exceeds 6ppm you will have a similar problem so it also needs to be kept below that. Nitrites are sunlight sensitive and if exposed to direct sun they will die. This is one reason we keep the fish tank covered. If you have a high nitrite spike or level, remove the cover from your tank to allow the sun to kill some off. The nitrites are eventually converted into Nitrates. This is the food used up by the plants. A system can generally handle a nitrate level up to 50ppm. If the levels begin to reach this or higher you would need to add more plants, pour some into a wicking bed, or harvest some fish. Worms are also a vital part of your system. They live in the bottom of the grow bed media and breakdown the solid matter converting it to a wonderful plant food. Another very important part of the system is your pH level. The best range is 6.4 to 7.0 but it can vary as much as 6.0 to 8.0 and still not cause harm to the system. There are a multitude of factors that move pH: gravel of media, original tap water used, tanks, plumbing, etc. Adjusting pH can be done many ways but you need to avoid things like lemon juice or similar citric acid as they can kill your bacterial processes completely. Our kits include a very simple explanation and ways to adjust it. For example, crushed egg shells are a wonderful pH buffer as are oyster shells and lime.
The media filled grow bed is actually a Bio-Filter that acts as a conversion chamber for the bacterial processes. The gravel or hydroton pebbles are simply a place where this can take place. The water level surges up and down as the pump slowly fills the bed and the auto siphon triggers a quick draining of the bed. The water level stays below the surface of the top to avoid algae from growing on the top of the bed. The plants are watered every hour and once they send down a tap root they drink anytime they like. As the water leaves the bed it dumps into the floating raft tanks. Here the filtered water flows over the roots and provides nutrients for those plants before ultimately returning back to the fish tank. If a buildup of solids happen in the raft beds, guppies may be added to it. The whole system is closed loop that only needs water when some has been lost to evaporation. Depending on how hot your climate is, this is very litte. It has been estimated that Aquaponics vs. Conventional gardening uses 90% less water. Any chemicals added to the system can kill your fish- this includes Chlorine which is in most all city water. If your water is chlorinated, we offer a filter that will remove the chlorine from.
If you are reading this and plan to purchase one of our kits, don’t bother with taking notes or remembering ppm levels. All of that is covered in the owners manual, training videos, and worksheets with exactly what to do to get your system up & running quickly and then how to maintain it daily. Concerning daily maintenance, that mostly involves feeding your fish and making sure the pumps are running ok. For longer term maintenance, on a weekly or bi-weekly basis it is good to test your water with the kit we include and to lightly brush the fish tank to stir up the sediment. The sediment is then pumped into the growbeds where it is transformed into plant food.