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!

Garden Update: The Setup!

If you have been following us on Instagram, you know we have a lovely 4’x8’ garden plot in Peterson Garden Project’s Vedgewater garden. Vedgewater is at the corner of Broadway and Magnolia and has ~180 plots. The land is on rent from Loyola, and this is their second year in operation. I’m hoping--pretty securely because I’ve seen several groups from Loyola working in the garden--that PGP’s lease on the space will be renewed. This is the closest community garden to our house and it’s almost like having a backyard garden. I started my garden planning back in March. I knew I would be growing things this year, because it was the first time in four years I would not be picking up and moving somewhere else. I got a huge stack of urban/small space/container gardening books out of the library. My favorite of all was definitely Grow Great Grub by Gayla Trail. Briefly, because this was not meant to be a book review post, this book is great because it goes through prepping a raised bed or container garden, the pests you might encounter, and the natural fertilizers you can use. Plus, it has plant-by-plant breakdowns of what you need to know to raise them. It’s super informative, and while I read it cover to cover once, I wanted to reference it so many times after returning it to the library that I just went and bought it.

Check out our seedlings!

Check out our seedlings!

Armed with knowledge, I set about the process of buying seeds and starting seedlings. I got seeds from three sources. First, I found organic heirloom seeds from Kenyon Organics on Etsy. I bought eggplant, cucumber, kale, chard, peppers, broccoli, basil, and three different types of tomatoes. Around the last week of March, I planted tomatoes, eggplant, peppers, and broccoli from seed indoors. I used toilet paper rolls as seedling packs, and filled them with organic seeding soil. I had also purchased a seedling pot maker from Burpee, and used that when I ran out of toilet paper rolls. The toilet paper rolls seemed like an awesome idea; it was re-purposing, biodegradable, and about the right size. However, all the toilet paper rolls developed mold on the outside. They also started to unwind, which made watering difficult because the water would just pour out the top. I recommend the pot maker or just saving the containers from store bought seedlings, which is what I will mostly use next year. Kristl has an Ott lamp for crafting which I used as a makeshift grow light. I wasn’t growing that much, so it was the perfect size.

Back to the story... The peppers and eggplants never came up. The tomatoes all sprouted and grew pretty well, as did the broccoli. We went to the orientation before April 22, when the gardens opened. We got a garden plot assigned to us. We were ready. Peterson Garden Project had a giant plant sale the weekend of Mother’s Day. We bought two more tomatoes, four cucumbers, two eggplants, and three pepper plants. I also got two kinds of lettuce and arugula for our porch plant boxes.

Look at that fresh garden

Look at that fresh garden

It was starting to get warm, so I began to get antsy about planting, even though most of my sources were saying to wait until after Memorial day for transplants. I got Kristl and all the seedlings outside to the garden one evening mid May, and we put everything we had in the ground. Later that evening, there was a huge storm, and it really knocked our plants around. Only two tomatoes and two peppers survived from that initial planting. Our plot belonged to someone else last year, so there were strawberries, oregano, and parsley which were wholly unfazed, but it was back to the start for almost everything we planted. Lesson learned.

Luckily, the farm we have our CSA through--Angelic Organics--sent us an email offering free seedlings out at the farm. I also learned that the Bonnie plants sold at Home Depot are raised organically and they have heirloom varieties. I purchased some organic bush bean, beet, and lettuce seeds from Burpee, and calendula (a flower used to speed healing for burns and cuts) from Seed Savers Exchange. We came home from the CSA farm with beets, corn, green onions, and a couple small tomatoes. We grabbed some kale seedlings from Whole Foods, broccoli from Matty K's on Lincoln, and eggplant, tomatoes, and a jalapeno from Home Depot.

By the first of June, we had planted almost everything except the hot weather plants (peppers, eggplant, tomatoes). I took a beginner class from PGP, and they said to try not to plant those types of plants until it’s good and hot or they won’t thrive. So, I didn't put them in until June 10th.  At the moment, I feel like things are going pretty well. All the plants look relatively healthy and all the seeds I have planted have come up. The strawberries have already given us six impossibly delicious, plump berries. We have had enough kale to serve as a vegetable at dinner, and we've been sprinkling fresh oregano into lots of things.

Our little deck garden really grows

Our little deck garden really grows

The lettuces on the porch are going wild! Kristl had a poached egg and arugula sandwich on her sourdough bread and it looked delicious. The real question now is how these hot weather plants will deal with the persistently cool temperatures. We have had some really discouraging moments so far in this growing season, but the best advice I probably got at my beginner’s class was not to get emotionally attached to the vegetables. If they die because of weather or some hungry critter, that is out of my hands. My job is to make sure they are fed, watered and protected from weeds. If they don't make it, I can always plow them under and start over with something new.

Going forward, I will try to give you a garden update every 2-3 weeks. I want you to keep up with the mistakes and victories I am having on the agricultural front. I’m trying to be conscious of mistakes I may be making. I’m not trying to come off as a master gardener (although I would very much like to become one someday). I’m just an amateur trying to grow some food to fill my kitchen. Hopefully, I will learn some tricks to make the produce produced outweigh the cost of seeds, seedlings, and supplies. And hopefully, it will get into the 80's for a couple months so our big yield, hot weather crops will have a fighting chance!

Until next time, happy growing! And eating!

Everything's lookin' good!

Everything's lookin' good!