Aquaponics in a Nutshell

Tilapia enjoying a nice morning swim My new life as an urban farmer is off to an excellent start.  I am making friends and, everywhere I look in Chicago, there are Windy City Harvest graduates doing excellent things to improve the food system.  I am on a good track to make the difference I feel compelled to make.

When I tell people about my program, I usually mention the aquaponics system at WCH, because it is a bit of a buzzword, especially as marijuana becomes gradually more legal around the country.*  You can absolutely use aquaponics to grow pot, but that's not really why it was designed.  We had a lecture on aquaponics today, and it was incredibly illuminating, and I'm not just talking about grow lights (haha!).

The guy who designed and runs the aquaponic system at WCH is a very knowledgeable individual named Andy.  We are not formally trained in aquaponics as part of our certificate program, but he said that the same science behind horticulture follows through to aquaponics and he's totally willing to teach people the basics one-on-one as time allows.  So, I only know what Andy was able to squeeze into a 1.5 hour lecture, but I will do my best to regurgitate the main points below.

First, where does the word "aquaponics" come from?  Well, there was hydroponics, the growing of plants in nutrient solution without soil, and there was aquaculture, the raising of fish in pools for the sake of food.  Both of these systems of food production, while innovative and interesting to think about, are immensely wasteful.  Hydroponics doesn't really have a good solution for what to do with plant waste water, it's very costly to set up, and the systems are very susceptible to mold issues. Aquaculture is a big polluter; you are essentially setting up a cattle feed lot for fish. Aquaponics, however, uses the waste nutrients from the plants to nourish the fish, and the waste from the fish to feed the plants. The crucible for development in aquaponics was the Virgin Islands in the 1970's.  It is really something we can thank the hippies for.

It is a bit more complicated than that, and you do have to feed the fish, but the cycle is way more sustainable than keeping the two separate.  The water that starts in the system stays in the system.  The only waste is a little solid waste from the fish, but there are ways around that as well.  Thus, the number one advantage to an aquaponic system is water conservation.  In addition, you don't need soil, you minimize pollutants going into the ground water, and the systems are incredibly adaptable and scale-able. Andy gave us an example of a home sized system, with a 10 gallon tank for a couple fish and a plastic tub on top for the plants.  You could have fresh basil, mint, bok choy, and some types of lettuce year round with this type of set up.  The initial set-up cost would be around $50 and that would pay for itself in a winter or two.

Individual home-sized aquaponic set-up

There are challenges to this type of system, as there are with anything.  It takes a bit of an engineering mind to build out a system to begin with, and evidently sometimes you don't know if you are doing something wrong until basically the whole system fails.  I mean, pretty much any science/trade/field has critical points of failure, but in this case, you could lose a lot of time and money if the system you put together has a critical flaw.

Once your system is set up, you become the grandmaster of tedious balance of pH and nutrients.  Andy showed us a really lovely chart that lists the 10 most essential nutrients for plants and the pH at which they are most available to the plants in solution.  It is in the slightly left of neutral range of 6.5 to 7 pH.  Any more acidic and things start to die.  I didn't take great notes on the actual processes and chemical conversions that are going on, but the basic cycle is as follows: feed fish, fish exhale ammonia through gills, ammonia is consumed by nitrosomous bacteria which turn it into nitrites, which nitrobacter bacteria eat and turn into nitrates which are the lovely nitrogen rich compounds that make plants super happy. Most systems do produce some waste at this point, which can be composted. However, at WCH they have an intermediary bed system, which has different plants in coconut coir for aeration, sitting in puffed shale that has red composting worms living in it. The worms feast on the extra bacteria and waste from the fish, so the system itself has basically no solid waste.  The other boon to this approach is these shale composing beds can support more intense root systems. So you can grow tomatoes, hot peppers, peas, and so on, making the whole system more profitable and/or delicious, depending on your perspective.

So, basically, that's aquaponics in a nutshell.  If you have a flair for tinkering with pipes and fish and plants, it might be a good hobby for you.  Some folks who do aquaponics grow enough fish to sell them to processing companies, but it's mostly tilapia, and the vast majority of tilapia are being grown way more cheaply in other countries in polluted waters. Andy says that WCH is planning on moving from tilapia to koi, mostly because they don't grow enough fish to keep a regular distributor.  Koi can be sold for way more money as ornamental fish once they outgrow our aquaponics system.

See more pictures below and let me know if you have other questions about aquaponics.  I'm soon to learn all about soil science, so I will have a better idea of what specific types of plants need in their soil at an elemental level.  Exciting stuff!

Basil growing in the floating beds

Cucumbers growing in the media beds, fed by the worms

Sump and pump directly below the media beds

* I honestly know nothing about marijuana, having never touched the stuff, but you do you, friends!

The Bitten Word's Cover to Cover Challenge

Fish and Chips with Malt Vinegar Mayonnaise
Fish and Chips with Malt Vinegar Mayonnaise

Most of y'all probably don't know this, but The Bitten Word is one of my favorite blogs. They did a cover to cover challenge last year, in which people were assigned one dish to cook from one of six magazines, the goal being to feature every recipe in those six magazines. I really enjoyed reading everyone's experiences and swore that I would participate if they did it again. Well, this year they did, and we signed up!

Instead of cooking all the recipes from six magazines, they decided to cook all the recipes from the September issue of Bon Appétit, and instead of having one recipe per person, they assigned multiple people the same recipe. That way they didn't have to cap the number of participants, and if for some reason someone didn't get a chance to make their assigned recipe, they could be sure it would still be covered.

We got the email with our assignment on Thursday, August 29. We'd planned to cook on Labor Day, but an impromptu cookout with friends pre-empted our cooking time. The submissions were due on Friday, 9/6, and Rachel had a terrible sinus infection all week, so we weren't sure we'd actually get a chance to cook. In fact, we'd kind of given up hope of submitting it to The Bitten Word, but pledged to cook it sometime to feature it here. Well, perfectionist that I am, Thursday came and I decided that I wanted to do it, whether or not Rachel could help me.

We actually had a choice between two recipes - Fish and Chips with Malt Vinegar Mayonnaise and Striped Bass with Lime Broth - because I'd requested an alcohol-free recipe and the fish and chips is made with lager. I let them know and they offered us the option of making the fish and chips with alcohol-free lager or making the striped bass. When looking for ingredients, we saw that the bass was $29.99/lb and the cod was $10.99/lb, so that made our decision for us.

The first step is to make the mayo. I've made mayo in the food processor before, but the recipe called for whisking by hand, so I figured I'd try it. Listen. I'm right-dominant. Like, extremely right-dominant. I'd try to switch to my left hand to give my right arm a break and it was like my brain couldn't control the left side of my body. I'd attempt to whisk, oil and egg bits would fly out of the bowl, so I'd switch back to my right hand. This happened a few times before I just gave up and whisked the heck out of it with my right hand, achy, shaking forearm be damned. Let me tell you, though, this mayonnaise was delicious.

The recipe recommended we serve the fish with french fries. Since I had never fried anything in my life, Rachel had only fried doughnuts, AND Rachel was sick and unable to help very much, we cheated and bought frozen crinkle cut fries. We did fry them in the oil, which made them extra crispy. We couldn't wait to try the mayo, so we ate a LOT of fries with mayo while making the rest of the meal.

Clumpy Batter
Clumpy Batter

Rachel cut up the fish (we wish we'd done smaller pieces than we did), while I worked on the batter. Whisking the dry ingredients was fine, when it came time to add the beer, club soda, and vinegar, it turned into a lumpy mess. I never did get the batter to be all that smooth; it was a weird combination of liquidy and lumpy. Next, we seasoned the fish with salt and pepper, dredged it in the corn flour, and dipped it in the batter.

Fish, corn flour, batter
Fish, corn flour, batter

Now we're getting to the exciting part - the actual frying! First off, we used a 3.5 quart dutch oven to fry. The recipe called for "about 4 cups" of oil and says it should be 3" in a large pot. We used 4 cups of organic safflower oil and it was maybe 2" deep. I'm still confused by how those measurements were supposed to work out. We were waiting for the 2" of oil to get up to temperature (375°), when all of a sudden it shot way past 400°. Damn it. We turned off the heat and waited for it to cool off. When it did, we turned the heat back on and put the first few pieces of fish in. Rachel helped with timing how long the fish was in the oil and putting it on a paper-towel-lined baking sheet when it was done. We had a heck of a time keeping the oil temperature consistent. It always seemed to be at 350° or 400°...375° was an elusive, mysterious, unattainable thing. We had to do 5-6 batches of frying, which took longer than we expected, but the fish looked beautiful.  The frying part wasn't really difficult at all, but we never did really get the hang of dropping the fish in the oil without it splattering back at us.

Frying the fish
Frying the fish

Now for the moment of truth! We plated two pieces of fish, some fries, lemon wedges, and the mayonnaise. We topped the fish with chopped dill, but completely forgot the sea salt and the Old Bay. Whoops. Having almost completely filled up on fries and mayo, we shared the one plate and declared the meal delicious. It was a fun stretch for us to make something like this, since neither of us ever really think to order fish and chips. The mayonnaise was definitely the best part of the recipe (though when I went to use it for some leftovers the next day, it had broken! I have to figure out what went wrong).

We definitely should have halved the recipe. Not only did it make way more fish than we could possibly eat, but it made a ridiculous amount of batter. If I were to make it again for just the two of us, I would have halved the amount of fish and quartered the batter recipe. We tried to fry the extra batter into some sort of malt vinegar fritter surprise, but the batter seemed to both liquify and become lumpier as soon as it hit the oil. It was unappetizing, to say the least.

We dropped off most of the leftovers with our friend Jess later that night. Almost as soon as we got back in the car, we got this text: "OMG. That's like legit delicious restaurant quality. I just devoured half of that! YUM. Thank you! It was so amazing I stood up and ate it in the kitchen. I'm lucky you two are my friends." We couldn't have asked for a better review!

Read Before You Eat: Sushi

Disclaimer: As you may know, sushi does not literally refer to raw fish.  Sushi refers to a piece of seafood or other item draped across a bed of packed sticky rice dabbed with wasabi. What Americans typically call sushi is actually maki, and that refers to fish and vegetables rolled together with rice in seaweed sheets.  Finally, sashimi (pictured below) is just the fish, and it is usually served with soy sauce and wasabi for dipping.  So, as you go through this post, please note that I am using "sushi" as a blanket term for all three items, but the concern is with the fish being used in these dishes. 

Hi, Rachel here. I'm going to tell you a little story about sushi. When asked to make a list of foods that I love, sushi is squarely in the top ten every time. I had my first sushi when I was a senior in high school.  It was before sushi was really popular, and we didn't have really any sushi options out in the suburbs. My friends and I took the train into the city and went to a sushi place in Lakeview. My mother hates fish, and holds any seafood--raw or otherwise--highly suspect, so I had her whispering in the back of my head that eating raw fish would certainly result in an early demise. Mother-induced anxiety notwithstanding, I tried several different rolls that day, and I was hooked.

Sashimi at Next, one of the few places in the Midwest I feel comfortable eating raw fish.
Sashimi at Next, one of the few places in the Midwest I feel comfortable eating raw fish.

Fitting with my enthusiasm for basically any food I love, I ate sushi everywhere I went: Chicago, Grand Rapids, Toledo, Denver, etc. I even had a make-your-own sushi party for my 24th birthday. I spent a summer in Japan, and of course, I ate fresh, flavorful sushi there. Sushi in Japan is not a daily occurrence, it's more of a special occasion food. One morning, we had the opportunity to visit the Tsukiji fish market in Tokyo and eat fresh, never frozen tuna. Talk about an idyllic experience. Another summer, I lived in San Francisco, where there are dozens of sushi restaurants, and ample opportunity for fresh, local sushi.  Tokyo and San Francisco were completely appropriate places to eat sushi, sadly, the Midwest was not.

Gradually, though, and somewhat against my will, I started to learn a series of facts which have made it very difficult for me to eat sushi fish, especially tuna. Tuna (bigeye, blue fin, and yellow fin) is relentlessly over-fished. They are often fished for using giant trolling nets.  The end result being any and all fish swimming among the tuna are trapped and killed as well. This includes everyone's favorite underwater mammal, the dolphin, which are easily the next most intelligent species on the planet after humans. Also, juvenile tuna are caught along with the adults, and they are not big enough to be worth a good market price, but they are not thrown back because the fishing method does not allow that type of discretion. So, future generations of delicious, flavorful tuna are being stunted by these fishing methods. 

Delicious, flavorful, and over-fished though they may be, there are reasons not to eat tuna for your own health. You ever wonder why pregnant ladies are not supposed to eat fish? It's because of mercury, or rather methylmercury, which is the form of mercury found in the ocean. It is absorbed by fish and passed on to humans when we eat the fish. We can all shrug off the effects of mercury on our systems, but you do not have to be completely toxic to have been affected by it. The EPA can back me up on this one. The mercury from industrial pollution gets dumped in the ocean, the little fish absorb it or eat it on the micro-organisms they consume, the bigger fish eat the little fish and all the mercury in the little fish stays in the bigger fish. A giant, cow-sized tuna would have the highest concentration of mercury. Giant, cow-sized tuna are the backbone of the sushi industry. (That and the fake crab sticks in the California rolls.)

Now you are thinking, well, there goes the spicy tuna roll, but everything else should be fine, right? I can still eat sushi minus tuna, right? Umm, well, basically all fish used in sushi are overfished, that's one thing.  Also you should know members of The Unification Church--a.k.a. the Moonies--own basically all the commercial fisheries in the world. This Chicago Tribune article is from 2006, but I have found no newer information to the contrary. While the article is fascinating, and certainly required reading for anyone who eats sushi, the Cliff Notes version goes as follows:  Rev. Sun Myung Moon, the self-proclaimed messiah, decided that controlling the world's fish markets would be an extremely profitable way to support his Unification Church. He decided this in the '70s and revealed his master plan to his church in the '80s (1980 to be exact, the transcript of his speech outlining the plan is here), and has been successfully living the dream ever since. For an idea of how ubiquitous Moon's True World Foods is, check out their company website. Regardless of how you may feel about the Unification Church and their practices, a monopoly in any business is dangerous and the danger is increased when it has to do with the food system. (See: anything Monsanto has ever done.)

Ok, so sushi is killing the oceans, potentially dangerous for consumption, and all the fish is owned by one giant corporation. Is it possible to find sushi that is safe, delicious, and sustainable? Yes, of course, you just have to know where to look. First off, the Monterrey Bay Aquarium Seafood Watch website will give you an idea of what fish are over-fished and which ones are still safe to eat. They also have a handy app for your smart phone. We also like this book, which goes through most seafood you might eat and ranks it accordingly to sustainability. Second, choosing to only eat sustainably caught sushi fish will require you to research your sushi restaurants. Kristl and I recently had local, line caught raw tuna in Hawaii that was as fresh and buttery as tuna ever was, and we were able to eat it without guilt. There are a few sustainable sushi restaurants in San Francisco I unfortunately didn't know about when I was there. If you are ever in San Fran, check out Tataki Sushi Bar. Do some research before you eat sushi, most major cities on the west coast have restaurants trying to provide some sort of sustainable raw fish option. When it comes down to it, though, here in the Midwest, where we are either landlocked or snuggling up to a tuna-free Great Lake, we have limited sushi options.

We both love sushi, and while sometimes the pull is too strong and we give in, we usually stick to a no-sushi diet in Chicago. We will occasionally go out to dinner with folks for sushi, but order only veggie and sustainable fish varieties. You would be surprised how delicious some sweet potato tempura or sauteed eggplant rolls can be, when you are looking for sushi flavor without the fish. For the most part, we are content to forgo sushi while in the Midwest, and eat lots of it when we are in places with sustainable sushi restaurants.

We didn't get into this at all, but there is also a serious problem with fish being mislabeled. You very well may not be eating the fish you think you are.  This NPR report is a great primer on the subject.