Stat Counter

Friday, June 29, 2012

What is Aquaponics?

There is a new form of agriculture running around that may help with tight spaces and poor land.  This agriculture is called aquaponics, and it is a mixture of aquaculture (raising fish or aquatic animals) with hydroponics (growing plants without soil).  What aquaponics allows is for the waste products of the fish, mostly ammonia, to be converted into nitrite and then into nitrate so that the plants can use this form of nitrogen to grow.  This allows for the fish wastes, which otherwise can be quite harmful to the environment, to be used, while encouraging the growth of plants in a medium that is usually difficult to perfect.

Basically it works like this.  You feed fish.  Fish are one of the best sources of animal protien because they have a high conversion ratio, in other words it doesn't take a lot of fish food to make a lot of fish.  The fish do produce large amounts of ammonia though, and ammonia is extremely toxic to them.  Luckily there is a group of bacteria that convert ammonia into nitrate, and another group that convert nitrite into nitrate.  Now nitrates are still a big pollutant, and too much can harm the fish, so how do we solve that problem.

By growing plants of course.  Almost everyone has seen what high nitrogen fertilizers can do to plant growth.  Who hasn't wished that their plants could shoot up green and healthy almost overnight.  The nitrates are a form of nitrogen that the plants can easily use, so the nitrates are removed from the water and provide a perfect fertilizer for the plants.  Now the plants need more than just nitrogen, they also need phosporus, potassium and all sorts of trace minerals, so this is not a perfect set up, but it is better than many ways of growing plants.  In addition to having ample nitrogen available, the plants are watered nearly constantly and so never undergo the water stress that can severly limit the growth of a normal garden. 

This system will never replace mainstream agriculture because you will always need something to feed the fish, and the nitrogen loving plants are typically leafy green vegetables rather than fruiting vegetables (like tomatoes, and peppers) but there are many ways that aquaponics can be helpful.  Tomatoes, peppers and other vegetables can be grown aquaponically, but not as well as leafy greens.  In dry environments aquaponics is useful because the water is right where the plants need it and is recycled, only being used by evaporation, transpiration, or plant growth; never by being absorbed into the soil.  In urban areas, the large amount of production from a small space can be a God-send.  And for homesteaders, being able to provide a large portion of your food, both vegetable and animal for small input in terms of fertilizers, time, and money is always a blessing. 

There are hundreds of different aquaponics systems around the world, and they are almost entirely home-brewed, that is, created by the people who use them.  These systems all have their positives and negatives, but they all help to accomplish something that their owners see as necessary.  Perhaps aquaponics could help people take more charge of the food that they consume, and provide a healthier more varied diet for a large number of people.

To see some books on aquaponics please visit http://uncommonskills.com/category/garden/aquaponics/

For some great examples of aquaponic system and how they are used (along with some free info on aquaponics) visit http://www.fastonline.com/ or http://www.backyardaquaponics.com/.  Both are great resources for those thinking of setting up an aquaponics system.

As always

Live a Hands-on Life

http://www.uncommonskills.com/