Last summer, I began to research this “new” gardening technique called aquaponics. To give a quick overview, it’s a closed-loop system of gardening: you have a supply of fish inside a separate tank, typically below a grow bed that’s either filled with media (like rocks or coconut coir) or has a raft floating above the water. The water from the fish tank, filled with waste, is then pumped into the grow beds for a “flood” where the water is taken up by the plants, then filtered through the rocks with worms to bring the clean water back to the fish. In a fully cycled system (meaning you have fish producing waste and bacteria colonies converting that waste into fertilizer) you don’t need to add any supplements, and plants don’t have to compete for nutrients since the water is evenly distributed to all the plants, then drained and renewed every hour. Which means that not only can you plant seeds more closely together, but they also grow up to twice as fast as conventional dirt gardening. At first, I doubted the claims as exaggeration. Yet now, being six months into my system and seeing it *almost* fully cycled, I’m regularly amazed at what it can produce!
So how did I get here? In the beginning I browsed a few forums, but the chat was so technical with terms I’ve never seen that I got confused and overwhelmed quickly. I turned to YouTube, which is great for beginners. Yet there were still so many different options for building your own system. You can use IBC totes, or fiberglass, or build your own and line them. Even with lining them, you had so many options! It just became a bit too much. I wanted to get started, and knew I wanted my own system, but I didn’t want to have to study for several months just to figure out how to put the darn thing together. So, I started with a greenhouse. I chose Ana White’s Barn Style Greenhouse because it’s compact, affordably maximizes materials, and frankly, I trust Ana. Nearly everything in my home is from an Ana White plan! I spent around $800 on supplies, and after a two weeks of working on days my two pre-schoolers were in a Kid’s Day Out program, I had the greenhouse built.
The greenhouse is 10 feet wide by 12 feet long, and I modified the sides to be able to be propped open for ventilation.
Now for the system. It was just too overwhelming to think about coming up with my own design, so I purchased a DIY tutorial from Endless Food Systems for $40. It was money very well spent! It had everything I needed to know to get started. I had to tweak it just a bit to fit into my greenhouse, by making two of the beds about a foot shorter than the plan. This left me with roughly 60 square feet of grow area. I started by purchasing a 300 gallon stock tank from my local Tractor Supply.
Next it was time to build my first grow bed. The plan uses 2×12 lumber, which is extremely heavy. If I were to build this again, I would definitely add more supports to keep it from sagging from all the weight.
Before I knew it, I had the grow beds and sump tanks (where you keep all the extra water to fill up the grow beds) built and ready to line.
Choosing a liner was tougher than I thought. One of the downfalls of aquaponics is that you really can’t get away from plastics. Be it the plumbing (galvanized and copper poison fish) or the tank, and even the growing beds, you have to keep it waterproofed. That means plastic. So I hemmed and I hawed, and I decided to ask a friend who is an environmental engineer. I sent her a few different options, she looked up the materials, and suggested I use DuraSkrim pond liner. This is what the pros use for organic certification, so I’m happy with my choice. They’ve come out with a new product now that’s thinner and easier to work with. I would definitely recommend that, because the DuraSkrim is ridiculously annoying to work with. But in the end, I salvaged what I could, and got this sucker lined!
After lining all the beds, we ran the plumbing lines. I decided to use polyethylene pipe for all the 1″ and 3/4″ lines and connections because it can withstand higher temperatures than PVC and isn’t quite as volatile. Plus it’s really flexible, which is nice for maneuvering as well as not worrying so much about freezing. I couldn’t find any 2″ PE connections, so the sump tanks had to have PVC connecting them. I hate it. They’re always leaking and cracking. I’m planning to redo the plumbing sometime this fall when it’s cooler.
Once I had everything hooked up, I did a quick leak check, then it was time to fill ‘er up! I searched high and low for a good, affordable media for the grow beds. I chose media because you can grow things more easily with larger root systems, like tomatoes and okra and corn and such. Rafts tend to be better for things like greens and herbs. You need your media to be pH neutral, and a quick way to test for that is to drop a piece into a cup of vinegar. If it fizzes, you don’t want it. I ended up on crushed red granite. I did the test and it didn’t fizz, so I spent $80 on two cubic yards and filled up all three beds. It took so much time, because I had to rinse the rock off first. I apparently didn’t rinse them quite well enough, because my water was murky for some time afterwards. I’m also not convinced it’s completely pH neutral as I have some trouble keeping the pH below 8, and 7 is the ideal for aquaponics. 8 is good for fish, not so much for plants. It’s a work in progress.
So, the system is built! I filled the tank up with water then started adding it to my grow beds. Once it looked filled I ran the pump for a couple of days to make sure I had the right flood and drain patterns going. Then, it was time to add in some fish. We decided to grab a couple of buckets of established goldfish from our stock tanks on the property to really help get this thing moving along. Once they stopped dying (and we only lost a couple in the beginning) I bought a few koi from our local pet store. Then over time I added more goldfish and koi, building up to my current population of about 8 koi and 30 goldfish. I’m trying to build a school of fish the appropriate size for my tank once fully grown, so I didn’t want to add in too many and have to try thinning them out later.
It’s been six months since my first seedling, and I honestly couldn’t be happier. Well, maybe if I had a few tomatoes 😉 But really, the performance of this system has been amazing. I’ve had a few learning curves to figure out with the whole ammonia->bacteria cycle, and hit a few road blocks. But overall, the system is thriving. I have had about 10 pounds of produce harvested so far, and much much more actually growing. I’m trying to keep things stocked well for the whole cycle to thrive. It’s really exciting to see things grow! I have a couple of dwarf banana trees that are doing well, a baby cranberry bush, lots of perennial medicinal herbs and some quick greens along with tomatoes, beans, peas, cucumbers and okra. Right now the chard is my top performer, with mustard being a close second. The rest is catching up as I strive to get the nutritional balances right.
Total expenses for the greenhouse and system, including plants and supplements (while things were getting started) was just over $2300. I’m happy with that, overall, because buying something this size, including the greenhouse, would easily double that cost. I’m hoping that it will prove itself in the long run and provide us with an abundance of fresh produce over the years. I’m planning to keep records to compare, and hopefully it will outshine the dirt garden so much that I can convince my family that we obviously need another AP system and just ditch the dirt forever!