Thursday, May 5, 2011

Growing Power with high tunnel aquaponics

Growing Power, Inc is an awesome social organization based out of Milwaukee that uses high tunnel aquaponics to great effect, producing upwards of 10 million pounds of food per year out of their ultra-intensive 3-acre urban farm.

The founder, Will Allen, is a MacArthur Fellow, and for good reason:



Here's a short overview of the aquaponics aspect of their operation:

Tuesday, April 26, 2011

The Postives of High Tunnel Aquaponics

1) Allows for economical year-round food production. The water in the system serves as a large thermal mass that traps heat during the day and keeps the environment warm enough during winter nights to support continuous growing.

2) Drastically reduces pollution of crops. First, it keeps contaminated rainwater off of them. Second, it gives us the opportunity to clean the internal environment up a bit for them. If we pull outside air through a filtration system and blow this clean air into the tunnel, then unwanted pollution would have a hard time seeping in, as any possible path in would be filled with clean air rushing out. If we complement the clean air with clean water pulled up from a deep well, we would have a pollution-free environment in which to grow our food. Pollination would then pose a problem, but if we make the buildings large enough to host small bee hives (or provide insulated tube pathways between smaller tunnels for them), we'd get fantastic pollination...and a tasty crop of honey.

3) Allows for massive localization of food production. Not only will produce be fresher, this allows consumers to have access to superior-tasting varieties of produce that aren't carried in our grocery stores because they don't ship well. On a community level, localized food production leads to other major benefits as well, such as enhanced local employment and all the positives that go along with that. It should also be noted that this would have a significant effect on social stability: our current food distribution system leaves our society susceptible to calamity (starvation and massive unrest) if shipping were to break down, whereas large-scale localized food production would make our society much more robust and capable of enduring much harsher conditions without disintegrating.

4) The need for supplemental irrigation is eliminated. The plants are already constantly and automatically irrigated.

5) The need for weed control is eliminated.  Since crops are predominantly grown in gravel, clay balls, or just water, the systems are initially weed free.  And since the high tunnel keeps weed seeds from blowing in, the systems stay weed free.

6) Pest problems are greatly reduced.  The high tunnel keeps bugs and vermin out (especially with the help of an electric fence).

7) Allows our food system to be far less dependent on fossil fuels. The amount of fossil fuels used for shipping food would be drastically reduced (no longer shipping hundreds/thousands of miles), as would the amount of fossil fuels used to fertilize the crops (no longer needing to use as much natural gas to make nitrogen fertilizer, since fish waste would supply more than enough nitrogen fertilizer).

8) Wind damage of crops is greatly reduced. The tunnel provides a sanctuary against the destructive force of winds, thereby allowing faster and lusher growth.

9) Water is conserved to an extreme degree. Recirculating aquaponics is often said to use about 95% less water than traditional irrigation farming. And by placing an aquaponics system in a high tunnel, I'm guessing that of that 5% that manages to enter the air through transpiration and evaporation, something like 95% of it is captured and reused in the winter when the tunnel is buttoned up fairly tight (the water condenses on the leaves and plastic film, then drips back down into the system). This means that a high tunnel aquaponics system can retain and recycle something on the order of 99.75% of its water during cool/cold weather. This number would be lower in warm weather, as more of the airborne water would be able to escape due to increased temps and increased ventilation, but water retention would still be impressively high.

10) Allows for enormous growth of inland fish/seafood production, which is immensely important since virtually all of the oceans' natural fish stocks are facing catastrophic collapse.

11) Allows families to provide the type of diet for themselves that many people suffering from Type 2 diabetes would require if meds were unavailable. (Discussed in another post here.)

12) Allows families to have a large supply of fresh water on hand for emergency use. It's true that a good high tunnel aquaponics system can generate enormous amounts of food, but since the human need for water is even more urgent than the need for food, it's nice that these systems double as massive stores of fresh water.

13) The system is ideal for organic food production. Since harsh fertilizers/pesticides/etc would hurt the fish, gentler organic methods are naturally preferred.

14) Provides a soothing and therapeutic sanctuary. It's tough to convey just how much pleasure I derive from my own high tunnel aquaponics system as a place to relax, think, and enjoy nature. I wish everyone could have such a place for themselves.

How I got involved in high tunnel aquaponics

I'm a pretty effusive optimist, but I'm also a bit of a doomer.

Problem: My dad has Type 2 diabetes. If his supply of medication were interrupted for an extended period (due to any number of realistic possible causes), how could we keep him alive and healthy?

Solution: Without medication, radical dietary changes would be necessary. A traditional Western, highly refined, carb-based diet would kill him in short order without his meds. To use metaphor: if proteins are logs, carbs are twigs, and fats are leaves, and if the ideal state for a Type 2 diabetic is a steady, slow-burning fire, then logs are the way to go. This means that his diet would need to be primarily protein. I've seen this referred to as the "face" diet, as in, "For Type 2 diabetics in scenarios without meds, if it doesn't have a face, don't eat it." Of course, the staple of meat would be supplemented by fresh fruits and vegetables (as much as his body deemed tolerable), but it would be wise to have the capacity to supply a pure meat diet for him if absolutely necessary for an extended period of time.

Problem: But if the supply of meds is interrupted for an extended period, then the supply of protein would almost certainly be interrupted as well. I don't live on a site with adequate room for growing livestock, and my dad doesn't want chickens, so how can I guarantee that he has access to an adequate supply of protein?

Solution: How about fish farming? This allows for the production of huge amounts of high quality protein in a limited space.

Problem: But growing fish in high densities requires massive water filtration; otherwise they'll quickly get sick and die. So how do I keep the water safely clean?

Solution: The toxicity of the water is caused by the accumulation of excess nutrients that can be used to grow plants. Therefore, if I add sufficient plants to the system, they'll uptake the excess nutrients and clean the water for the fish. (When I got online and began researching the concept of combining fish and plants in a symbiotic growing system, I learned that this method of growing is called aquaponics.)

Problem: How do I keep an aquaponics food production system going year round?

Solution: Enclose the aquaponics system in a greenhouse environment.

Problem: How do I do that effectively and economically?

Solution: Use a modified high tunnel as a passive solar greenhouse.

So that's what I'm doing.

Wednesday, April 20, 2011

Garden Aquaponics in the UK

Here's a blog about garden aquaponics in the UK. Some pics from their adventures:





Synaptoman likes high tunnels

There is another fellow in South Africa who likes to mix high tunnels and aquaponics. He is known as Synaptoman, and you can find his blog here.

Synaptoman's blog provides a wealth of interesting pics, stories, and insights into aquaponics. Here's a taste:









Aquaponics on GardenWeb

A poster on GardenWeb named tclynx (who has a nice website/blog here) shared these pics of an aquaponics system operating in a small tunnel: