Friends, to say it has been quite a week would be like saying Shawn White is a good snowboarder. First, there was the feature article in the food section of the local paper on Wednesday. Perhaps some of you have experienced the surreal nature of having your face splashed on the front page of a section of your local paper, but I hadn’t. It’s fun and exhilarating, but it throws you off balance at the same time, especially when you know that an article in the New York Times on Aquaponics was going to hit the next day. Friends would say “wow, that’s wonderful” and my response would be “thanks (but just wait until tomorrow.)”. Hopefully that didn’t sound ungrateful or arrogant, but it was the honest truth.
Then Thursday came, the article ran, and I think aquaponics in America has changed forever. It’s been the top 3 or 4 most emailed story in the Times for two days now. The tweets having been flying. People around this country are hearing about this amazing, simple, symbiotic growing method for the first time and having “aha” moments. Amazing. Incredible. My heart is full.
A friend pointed out this afternoon that there was an interesting dialog going on in the comments of the article which was probably an accurate representation of Q and A’s going on in households all around the country. While I promise not to get into the habit of cutting and pasting other’s writings and calling it a blog post, I want to highlight the response to those questions given Karen Swanberg, a wonderful member of the aquaponics community who I hope to meet some day. Many of you may have the same questions / issues and she did a wonderful job of concisely and, in my opinion accurately, addressing those questions and concerns in a way that I wanted to echo with this blog.
The purple print is from a comment from a NYT reader, followed by Karen’s response.
1) What feeds the plants is actually the large quantities of processed food being fed to the goldfish and Tilapia
There are many aquaponics (AP) people who are feeding their fish completely off of non-commercial resources. Many use red worms (composting worms) and black soldier fly larvae. Many grow duckweed and other water plants. Using the compostable scraps from nearby restaurants can often produce enough worms/larvae etc. to feed the fish.
2) And the plants can not grow using nitrogenous waste alone. Minerals are depleted from the water
Many of us use oyster shells to buffer the pH, and those shells contain many of the micronutrients that are needed. In addition, if you’re using the worms/larvae from 1) to feed your fish, the micronutrients from the original scraps come through the system, back to the plants.
I also throw a handful of greensand into my growbeds about once a month.
3) If the greenhouse plants are attacked by pests they will be difficult to eradicate without poisoning the system and killing the fish.
Most APers use various forms of integrated pest management. Companion planting, beneficial insects and the like. Pests are an issue, but it’s no different than any other growing endeavor. The inability to use pesticides is one of the advantages of the system. Pesticides and herbicides kill the bacteria that convert the fish poo into nitrates that the plants can use.
4) they are inherently much more complicated than the article implies and are not closed systems by any means.
But not as complicated as you are making them seem. (author’s note – read prior blog post on Aquaponics is not Difficult)
5) They require a substantial amount of energy to regulate. They must be operated in a heated greenhouse of some type in temperate climates, must have electric pumps for aeration and water circulation. The pH and hardness of the water must be controlled for the health of the fish and as David said they require outside sources of feed and nutrients for the fish and plants health. They are not closed systems.
Energy is needed, but it can be acquired through renewable means. Most of us use low-power pumps, and some APers have even used bicycle-powered generators to power their pumps.
We’ve forgotten how, but greenhouses can be run without a significant amount of external heat. There is a couple in Milan, Minnesota who are running a winter CSA out of a greenhouse, and they only use about $50 worth of propane *for the entire winter*.
pH and hardness can be controlled by what you choose to use as your growing medium. As I mentioned in the comment above, many use oyster shells in the mix, and that helps both pH and hardness. Carefully chosen gravel goes a long way.
6) Thank you, James Godsil, for mentioning Growing Power and Sweetwater Organics. (I am not associated with either of them.)
7) The tomato from the grocery store was grown in a greenhouse. How does an aquaponic tomato compare to a greenhouse tomato, especially if that tomato was grown in a cellar under florescent lights?
They compare very well. The bell peppers I’ve grown in my basement have been delicious, and this produce compares to soil-based produce in taste, nutrition and naturally-grown-ness. Sun is always better than artificial lights, but really, very little AP is done solely under artificial lights (that I know about, anyway). (author’s note – the heirloom tomatoes from my AP system have become a requested hostess gift instead of a bottle of wine. They are incredible.)
In addition, the tilapia grown in AP is high in Omega-3s and low in Omega-9s, unlike the farmed tilapia that you buy in the grocery store.
8) And to echo a comment above, hydroponics always require the addition of fertilizers to the water. Hydroponically grown produce has a lower nutrient content and has generally less favorable quality for appearance and texture
Do NOT conflate aquaponics and hydroponics. They have some features in common, but AP uses all-natural fertilizer and inputs, while hydroponics is by definition artificial. Produce from AP is much closer to the produce from an organic farm than it is to hydroponic produce.
9) I would never consider aqua/hydroponic produce to be “organic.”
AP systems are now being certified organic by the FDA.
“We will show you how we got our aquaponics farm USDA Organic Certified AND Food Safety Certified” The inputs used in hydroponics would kill an AP systems. You can’t use anything in AP that poison hydroponic and chemically-grown produce. It will kill the system.
10) By trying to maintain a constant temperature year round, this dramatically increase the amount of energy required to produce food, of any type.
There are non-electric ways to heat water. Solar water heaters, running the water underground to pick up ground heat, burying tanks… And, I also grow catfish in my AP systems. They are a natural fish here, and do not require any additional heat. Trout are also often used in AP systems, and they require extremely cold water.
11) The investment cost and ongoing energy requirements of food production must be lowered
We’re working on it! There are many active forums online that deal with these very things.
12) I was under the impression that tilapia are carnivorous fish,
Omnivorous. The babies (fry) need a lot of protein, but after that, they do just fine on non-meat-based food.
13) commercial tilapia farms are devastating to the environment
see above re: feeding AP fish from compost worms, black soldier fly larvae, duckweed and similar.
14) And they’re GOLDFISH. You can’t even eat them!
Well, you can. Carp is considered a delicacy in some places. Most of us just use goldfish to start our systems, though, because they’re cheap and tough. Then we graduate to tilapia, catfish, prawns… (author’s note – see prior post on To Eat or Not To Eat)
15) The strict environmental controls needed by the fish of course require a lot of electricity. And the greenhouse is, on my view, a remarkable waste of resources and money given the expected yields of such a system.
Again, see above. It is possible to do this, even in fricking cold climates, without huge energy inputs.
7) Nothing here about the introduction, presence or metabolic fate of antibiotics
Antibiotics would kill the bacteria which are the hidden engine of AP. Antibiotics can not be added to these systems.
18) Soil is great stuff. It buffers the availability of water and nutrients, buffers temperature extremes, and provides many other services that plants need. In hydroponic (or “aquaponic”) systems, every one of these services must be provided by the person overseeing the system.
The growing medium in AP is alive with bacteria, fungas and many of the other things that soil provides. Once the system is set up correctly, these issues are far smaller than they seem from the outside.
Check out this video: http://www.youtube.com/watch?v=HHiNiWtkDFk
At the end, the speaker shows plants grown in his AP system right next to plants grown in soil. Same plants, planted the same time. The soil ones are scrawny compared to the AP plants.
19) It’s a boondoggle, fit only for novelty use or very special agricultural situations involving very high-value crops sold to affluent consumers.
You’re wrong. AP produce can be produced very cheaply, and Growing Power provides jobs and produce to many inner-city, non-privileged people.
20) they are toys for the rich.
Absolutely not. The system Travis designed, barrelponics, can be built almost entirely from scrounged materials. There are a lot of middle-to-lower income people who are providing their families with the highest-possible-quality produce with very little expense from these systems.