After several years of working with experimental aquaponic systems, including the SPACE 200 and the Hi-SEAS X-30 systems, we began plans to build a system scaled to production volumes. To better understand the logistics for growing off-season produce in our region, we built a small demonstration system in our home shop. Our shop space has a fairly small footprint (12’ x 12’) with high ceilings (13’).
To capitalize on our headspace, we built the system to suspend from the ceiling which allowed us to conserve floor space for seed starting. Although this allowed us to make the most of the floor space, it turned out to be a dangerous and tedious arrangement for managing plants. To check on our crops, we had to climb a very tall ladder to see them and then climb down to move the ladder to check the next tower over. Although we saved space by building high, we were wasting a lot of time and energy due to inaccessibility, not to mention the safety risks involved with working on a ladder so often.
To solve this problem, Jeff implemented a winch system that raises and lowers the towers when we need check on the plants. There are still some balance issues to work out with the winch, which becomes messy when the rows are full of water. Perhaps we should have hung the towers at eye level from the beginning, but hopefully our mistakes will inform future developments.
We had some really interesting results with our Zero-G system. Basil grew quite well and definitely has potential for commercial production. Herbs are generally thought to do poorly in controlled environment systems. This is usually because the environment is too accommodating to induce the stresses required to stimulate essential oil production in herbs. Nonetheless, we were able to grow some very fragrant rosemary, basil and lavender. Perhaps the frequency of our LED lights helped stimulate essential oil production.
We also grew a few varieties of leafy greens, but they exhibited a very strange growth pattern of elongated nodes. I have read that this growth pattern occurs in soybeans when there is a non-ideal ratio of red to far red light used. The article stated that a certain threshold of blue light can remedy this problem. The next time we grow leafy greens I will try using a more complete spectrum. The leafy greens also had heavy issues with whiteflies and aphids. We didn’t see any insects on the herbs, probably because their essential oil production acted as a herbivore deterrence.
We shut the system down at the end of the winter when we started to focus our attention on outdoor crops. If we were to reboot the Zero-G, I would definitely want to adjust the aforementioned issues. But the most important change I would want to implement is USDA compliance practices so that we can feel more confident about the safety of the food we are producing.
We learned a lot and collected a lot of really great data with the Zero-G experimental system. We considered applying for the Growth Through Agriculture grant again this year, but when I was writing our proposal for a container sized production facility, I kept waking up in the middle of the night with a voice saying “Don’t do this!” After some soul searching, Jeff and I realized that we don’t necessarily want our lives to be about large scale crop production. We love to research, experiment and create. We decided to shift our focus and continue to experiment with controlled environment agriculture while sharing our experiences with the world.