What is Aquaponics?
Aquaponics is the combination of two distinct methods of raising food. Hydroponics, or growing plants in a soil-less medium. Usually clay pellets or gravel is used and then the plants being grown, are watered with a nutrient solution. Aquaculture which is the raising of fish, typically a food fish in tanks.
The problem is that with both production methods the nutrients become out of balance and must be dumped into the ecosystem. This causes nutrient rich waste water to be released into the environment, which is typically our waterways, which are unable to handle the increased nutrients which may then cause environmental damage! Excess nutrients ending up in our waterways is becoming a major ecological concern as evidenced by the annual mass fish die offs seen in the Gulf of Mexico annually. This mass die off is being attributed to production farming in the Midwest where large amounts of Ammonia are being pumped into the ground in order to provide enough nutrition for crops to grow to maturity.
In many parts of the United States particularly in California we are experiencing a drought. These drought conditions have caused many commercial farms to reduce production of crops due to water rationing. This in turn drives up prices and increases "food miles" as our food ends up having to be trucked in from not only other states but other countries as well. We are seeing a greater number of food product recalls due to these and a variety of other factors.
Agriculture in America has to change if it is to survive!
Backyard farming has seen a resurgence in the form of Square Foot Gardening, Container Gardening, Permaculture, Back Yard Gardening and the like but as such we are ill equipped to feed our own families let alone communities! With more and more people as our population increases and less farmland available to grow foodstuffs there is rapidly becoming a supply and demand problem that we will not be able to solve by ourselves!
But what if I were to tell you that even in the heart of a big city you can grow enough food for not only yourself but your local community as well? It will take a cooperative project spearheaded by ambitious individuals to push for and incorporate this change but not only is it doable but it is being done!
Aquaponics is the answer to our pending food disaster in this country! With Aquaponics you do not need a huge area to begin to grow food for yourself, it is water wise. Water wise farming is not only necessary in many parts of the country it is the make or break point in agriculture in this country!
In Aquaponics you grow a food fish in tanks that can be as small as 200 gallons and then the water is used in a re-circulating system that goes out to gravel growing beds and which in turn waters and feeds your food producing plants and then flows via gravity back into your fishtank. This gives clean fresh water back to the fish where they can continue to grow and thrive. You get fresh fish and produce from the same system! On average you get 3-4 times as many pounds of produce as you do fish. This means that several crops of produce can be grown from just one tank of Tilapia, Perch, Crappie, Bass, Bluegill, Catfish, Etc., For every gallon of fish tank you need at least one gallon of grow bed so you can see how much space for growing food this really can take care of! Personally I have used much smaller tanks than 200 gallons but I also have a traditional garden. With the smaller tanks you really have to pay close attention to water quality. The water may become out of balance, meaning that there may be an Ammonia spike due to several factors. When this occurs you have to do a partial water change in order to keep things healthy for your fish. In my case that means that I use this water to water my garden with. I still keep in mind our drought conditions here in Southern California where I live so I place this water into gallon jugs that have a couple of holes in the bottom and place these jugs next to my plants. This way I waste as little water as possible.
Now imagine for one moment here that you lived in an apartment building, you may say that you can't possibly garden in this situation. But here I am to tell you that more than likely you can! Does your building have a basement? Perhaps it has a flat roof with roof access Or what if the entire complex got together and rented one of the apartments Then in any of these situations you CAN grow both fish and vegetables for your entire complex, and perhaps some for the local food bank as well!
Fish are raised in tubs of at least 200 gallons and then channels can be made with large pvc pipes cut in half lengthwise and capped off at each end so that they don't leak. These pipes or conduits are raised higher than the water level of the fish tanks so that the water pumped through them can gravity feed back to the fish tanks.
Fig 1 shows an example of how this is done using 2 tanks.
The tank on the left is where the fish are raised and is the largest volume of the two tanks. The second tank is the sump and it collects the solid waste via the use of a bridge style pvc system which I will explain later. The second tank or sump will be used to pump the water into the growing beds, the reason for the sump is so that accumulated solid waste from the fish can be removed easily and the pump can be situated in such a way as to prevent it from being clogged by any fish that may be sucked into the intake or any other debris from the primary growing tank. This sump can be filled with filter material that can be removed for cleaning. It should also be equipped with a spigot for easy draining so that solid waste can be removed from time to time and used as fertilizer or fodder for composting worms.
The black line denotes the pressure line coming from the pump into the grow beds, the green denotes the pvc conduit grow beds, and the light blue is the return lines to the main fish tank. The pump can be on a timer so that it delivers water about four to six times in a twenty four hour period. In this type of system the only water loss is that lost through evaporation or plant respiration, hence it is very important that the level of the gravel be higher than the highest water level in the growing medium.
Aquaponics Part Two