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Aquaponics

I have been wanting to do a blog about this  topic since Natalie and I decided we needed to blog. You see in a previous life I worked as a fish facility manager. Once a week there was a farmers market downstairs and outside of our building. I never connected those dots.

When we moved to Iowa I came across a group Coalition to support Iowa Farmers. This group was actively providing educational resources and support for aquaculture in Iowa. They even hosted a conference in 2016 and another in 2017 on the topic. The conference was very informative and the networking was pretty good as well.

I also started paying attention to Practical Farmers of Iowa and looking at the regulatory picture for farms in general, livestock farms, vegetable farms, and organic farms. In a previous blog I mentioned going to events sponsored by these organizations. However there is no organization in Iowa that combines aquaculture and vegetable production. There are a couple of farms that do it.

So why combine them? As I see it you have the ability to produce ( with appropriate planning) enough high quality, organic, nutrient dense and healthy food on a smaller scale and with less environmental impact then traditional row farming. How?

The excrement from the fish becomes the fertilizer for the plants. The plants provide filtration and nutrient removal for the fish.  The end result is a cyclical relationship that poses unique challenges but also uses less resources then growing conventionally.

What do I mean when I say less resources? There are tanks and fish food and water and space. When compared to conventional farming aquaponics uses 85 to 90% less water than growing in ground. The reason is filtration and re circulation. The water from the fish is used to hydrate and to convey nutrients to plants which use very little water when you consider how much water is lost in conventional irrigation. Drip irrigation is more water efficient then overhead or flooding but still less efficient than aquaponics.  You do not need fertilizer as fish waste is converted to fertilizer by microbial action (fish waste is high in ammonia), which is converted to nitrites and then nitrates which are taken up by plants. The ammonia and nitrites are not fish safe so removing them is essential to growing fish. It is an example of one groups waste being another groups raw materials.

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The nature of aquaponics allows you to grow things closer as nutrient competition is removed from the equation and if designed appropriately light and ventilation is adequately addressed. You can grow more plants in a square foot of space than you can in the ground conventionally. Tanks are a cost but are more of a fixed expense than a recurring one. If they become recurring you need to really think about why your fish tanks are being abused so much. Water is an issue as it has to be of appropriate composition and temperature for both fish and plants.

Now that you have plants growing and you have your fish. As you harvest plants you can also cycle your fish and have a more healthy protein source. Tilapia is common but any fish can work as long as it is fresh water and it will grow at a temp appropriate for the plants you want to grow. I have heard people growing colder weather plants with cooler water fish successfully.

We will be constructing a small pilot aquaponics system in the future so stay tuned for that. This blog post is really just a primer for that post.

 

Doug

 

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How did we get here?

When I was in ST. Louis I worked in a research lab. Every week in the summer we had a farmers market downstairs. I LOVED doing my grocery shopping downstairs. I had a CSA I was a member of. There was a guy who sold the best Yogurt. FYI the best yogurt is windcrest dairy out of Trenton Illinois. Yea I am biased because it is soooooo good. Great people as well. Anyway. I would get enough yogurt for a week and my csa and had no need to really go to the grocery store. I would go to Soulard or my own small garden on occasion if I needed something more but most of my needs were covered.

Then we moved to Iowa. The land of farms with no food to eat. It was amazing how spoiled I had become. You never even think about it. Just go to the grocery store and pick up something which is trucked in from elsewhere. We did not have space to start with but the town we lived in had Community Garden space. You could really rent a plot for the season and it was cheap like $35 for a 20×50 plot. Now think about how much you could grow on something that size? You do not have that space or a community plot near? While we never used this service I did come close two seasons but one we were traveling a lot that summer and the second I was just to “busy”. In reality I did not want to bother with it cause I was still pouting about not having my CSA and Soulard and home garden.

Aerogardens are a good alternative. We bought one for our apt. We could produce about 2 salads a week using all the pods. That was not so bad and to have super fresh salads was awesome. I am not a huge iceburg lettuce fan so the aerogarden was a pretty good option. The down side was the lights were on for 17 hrs and while LED so little energy used it was bit of a light pollution issue in our kitchen at 3 am and bright as day in there.

So we bought our 5 acres. You can see the plot on a previous post. So we started a small 50×100 garden our first year. The sweet corn was pancaked by winds. We did get some but it was all laying down. Our squash did awesome. We had butternut, spaghetti, pie pumpkins, zucchini, summer squash. Our tomatoes did well enough to enjoy and even can some sauce.

The second season our squash did well again but trying a new technique we had significantly reduced yields. Our tomato produced okay but the green house gravel issue reduced those yields and pests got all of our corn. We did get black beans, garlic, potato, and wheat. We have expanded each year with the hopes to eventually provide our own food and sell at market the overage.  We have also begun looking at the legal aspect of farm production for sale. Including training on FSMA (Food Saftey Modernization Act).  Slowly we are meeting fellow producers and learning the market streams and how it all works. We have attended several conferences that I will post about in the future.

In a nut shell that is how we got here.