Home Hydroponics System
//:> The following is an ongoing chronicle of an experiment in hydroponics. It is part of a larger study to test a hypothesis that the home can be refined to generate much of its inhabitants own needs.
2019.5.1
With one eye always fixed on our environmental status, it seems to me that the area most potent in effectiveness and under-utilization is the point of consumption. Us consumers are finicky things. Considering the astronomical effort made in logistics: getting the food to us - the near-zero regard to waste - what we do with the packaging and unused commodity when we’re done with it - it would be so much simpler to cultivate what we can in our own homes.
While some exotic species of fruits and vegetables can be difficult to grow in a aquaponic or hydroponic environment, most of the produce we consume the most of actually thrive in these settings. Any home gardener will tell you that the experience of tasting homegrown produce is so vastly superior in taste and quality to store bought products. It turns out research nutritionists would say the same about the nutritional value of homegrown fruits and vegetables.
Wanting to try my hand at a home system, I first had to acknowledge that as far as green-thumbs went, mine was whatever the opposite of green is. I couldn’t keep a rock alive. So my first step was to build an understanding as to why. The answer was actually pretty simple - record keeping and consistency. My biggest error (which was quite consistent ironically) was that I didn’t remember exactly when I last watered a particular house plant nor did I understand the more basic nuances of individual species in regard to water needs. Like many, probably, I relied on the old finger in the soil trick, which is informative but hardly scientific.
Once I began understanding what each plant needed and when through proper record-keeping, it became second nature. This was substantiated by their well-being. But once I mastered this I became restless by what a pain in the butt it was to move all these plants outside - some of them pretty heavy - water/fertilize/repot/repeat. Plus it irritated me how inefficient it was. One of the first things I learned about plants is that water sitting at the bottom of a pot is a big no-no. It needs to flow through and fully saturate the soil but not pool (or else… dry rot. mold. death). This means that like ~80% of the water or fertilizer is flowing through and lost. I didn’t like that. I thought about some sort of rack where I can stack the smaller plants on top of the bigger plants so the water trickles through each pot like the cheese fountain at your cousin Vinny’s wedding. But again, this was still too inefficient. Some plants drink more than others and have different fertilization schedules. It made more sense to have a central pool that is treated and maintained and circulated to individual plants as needed and returned to the pool… sort of like your circulatory system.
I’m not that big of a nerd that I didn’t realize how ridiculous that sounded. They’re just house plants. Still, my interest was piqued… where would that make sense? A living wall… a wall or small space dedicated to food production that was nearby the kitchen. I’m hardly the first person to think of this, but naturally I wanted to approach my own system as if I were. Living on a plant-based diet for some time and eating lots of leafy greens and vegetables, which do well in these types of environments, I was going to give it a try.
Step 1 - Sketch, Interpret, Repeat
Building a structure like this needs planning, obviously, and while I’ve always been a leap-then-look rock star I’ve come to realize how much time can be saved by resisting the urge to just start and instead try to exhaust your thinking on the matter as best you can. What were the needs? What were the wants? I tend to make a list of features that includes every flashy bell and whistle I can think of, then eliminate the plan down to the simplest system possible. It is so easy to overwhelm the project with fancy trick shot design notes, but this almost always comes at the expense of actually finishing the project. Find the core function of a system and focus on refining that as best you can. You can always come back to add in features.
>>> As you can see from the diagram, my initial approach was to create an aquaponic system. This type of system is essentially a closed loop self-sustaining cycle where the nutrient-rich byproduct of the aquatic animals is used as the hydroponic base with which nitrifying bacteria convert ammonia into nitrates [wikipedia definition]. The only outside input is food for the fish to eat and temperature regulation of the water. Put another way, the fish defecate in the water, which is then pumped through the plant root system. The plant roots absorb all the nutrients from the defecation while neutralizing the ammonia - thus returning clean water back to the fish tank for them to swim happily ever after.
Step 2 - Build. Maintain.
While I don’t have any pictures that do the effort justice, I actually created and maintained this system for about two years before it experienced environment collapse. Friends had donated a tank and several guppies and I based the system off of that tank. Executing an aquaponic environment is not as simple as putting some plants in a fish tank. There is a stasis that must be found where the fish produce enough by product to feed the plants and the plants absorb enough of that ammonia to return fresh water to the fish. It requires constant pH and temperature monitoring in order to find that stasis.
2022.5.1
Feeling not so great about the fate of my loyal fish, I decided to try again but to take a simpler, hydroponic approach. This meant taking the fish out of the equation. My logic is that the aquaponic system is more complicated to maintain, and even when a balance is found within the ecosystem, there is still intervention required on behalf of the user. It would be at most as difficult as a hydroponic system, if not easier, to simply maintain the water-base with nutrient enrichment manually but without the risk of a cruel demise of aquacultural collapse.
<<< I would reuse the same tank as a reservoir for the nutrient enriched hydrate. This enriched water would be pumped up to an entry point in the trough and fed directly to a plant. As the water saturates the soil and trickles back to the trough it is led by gravity to a return port at the opposite end of the trough and flows back into the reservoir. Multiple troughs can be added and removed to the system as harvest and planting requires.
>>> The nutrient enriched hydrate is first treated to de-chlorinate the water. The enrichment is as follows:
Nitrogen N….. 12%
Phosphate P205….. 4%
Soluable Potassium K20….. 8%
Iron Fe….. .10%
Manganese Mn….. .05%
Zinc Zn….. .05%
The water is further oxygenated and agitated to maintain circulation in the reservoir. This prevents stale stagnant water from forming. UV lighting is used to kill bacteria generation in the pool.
Future Features
As I mentioned when I opened this project, it is best practice to simplify a project as much as possible and add advanced features after a core performance has been established and optimized. In the near-term, this project would benefit from the following…
Interchangeable Crops
At the moment the system is used to nurture ailing house plants (specifically Pothos, which are unreasonably sensitive). As the bugs are worked out, additional troughs will be added. The intent is to grow various species of lettuce - red leaf and romaine, hopefully - as well as nightshade species like tomatoes. These will each have their own trough, oriented horizontally and stacked vertically with dedicated irrigation lines. As each species needs planting, harvesting or general care, they can be removed from the system and tended to. It would be plug-and-play for easy use and maintenance.
Real-Time Environment Metrics and Control Systems
This would be embedded sensors for soil and water pH and temperature, moisture levels, and light exposure. The values of these would automate controls for each through a simple PID program.
