Giving you unmatched versatility, affordability and invaluable knowledge in the process, building a DIY aquaponics system is an excellent choice if you want to get into this superb style of gardening.
Now, even though going the DIY aquaponics route is a personal favorite and brings many benefits when compared to pre-built ones, you’ve got to arm yourself with knowledge before starting.
After learning the essentials, you’ve got to know how to put it all into practice and start building – and that’s where this article comes in.
Now let’s begin!
In recent years, aquaponics has become the most popular way of growing food in a sustainable manner. The system is a combination of aquaculture (raising edible fish) and hydroponics (growing vegetables in water) – hence its name.
It is deemed the most economical way of growing plants as it creates a self-sufficient system for both growing plants and rearing fish without releasing waste products. Users also grow much more food in a relatively small space compared to traditional gardening or farming.
Buying an aquaponics system can be fairly expensive, especially for those who want to embark on large-scale production of food. As such, many individuals have taken to DIY aquaponics and have since started building their very own systems.
Even though it requires more planning, time and effort, it rewards DIYers with a much more affordable cost, unmatched versatility (can be built to fit any space or requirement), a wealth of knowledge and practice gained and of course – the wonderful feeling of having completed your own project.
Next, we look at the first considerations you mast take before starting – where to place and how to construct a DIY aquaponics system.
It plays an integral role when setting up the system for the long-term. DIYers making the system for business require a larger space than those who are doing simple gardening. For example, those living in high rise buildings set up the system indoors, which means they have to install artificial lights and window lighting. I am fortunate to have a backyard where my plants get adequate sunlight.
The outdoor placement should also be feasible based on the climate. In Australia, the climate favors aquaponic gardening thus, farmers can grow produce all year round. Individuals residing in North America and Europe are compelled to relocate the systems indoors or simply place them in a greenhouse.
DIY aquaponics systems will include a raft or a grow bed (one floats over the water while the other gets water pumped into it), a fish tank, a food table (optional) and pumps. The user may decide to add other components based on environmental factors, personal preference or type of system. For example, people setting up the system in particularly cold climates build the aquaponics system in a greenhouse for year-round use or add temperature control and artificial lights to compensate.
Regardless of which type or style you go with, the main components stay the same. Let’s take a look at them and what they do before learning how to set them up.
A well-tuned system should support one pound of fish per gallon of water. For my system, however, I started off with one fish for every 10 gallons of water to create a balanced system. This way, the fish had more space to swim and live comfortably and eventually I added more fish over time after monitoring their progress.
Most DIYers set up 225-gallon square tanks or 55-gallon barrel containers, which make up the two standard sizes of food-grade tanks. When choosing a DIY aquaponics fish tank, ensure it was used to hold edible items in the past and not toxic matter that leaves harmful residue. An above-ground swimming pool may also function as a tank for very ambitious DIYers.
The vegetables require a water-resistant container that can hold the wet medium they will grow in. Many products are used for this purpose such as wooden boxes and metallic containers, among others. The simplest method is to construct shallow wooden boxes that are 6-10 inches deep like ordinary raised beds for vegetables and fit pond liner in them. This is a quick, easy and super economical choice.
The bed is filled with fine gravel, perlite or other inert growing media such as the popular clay pebbles. I found perlite extremely lightweight as it allowed me to elevate the beds off the ground with ease while fine gravel, even if incredibly cheap, was fairly heavy. Clay pebbles are a fantastic combination of both that works wonderfully well. Some DIYers also prefer using coco air due to its ability to retain air and moisture while others mix the three products.
The pump helps to circulate the water between the two components while keeping the self-sustaining system fresh and running smoothly. A solar-powered pump is ideal for setting up a self-sufficient aquaponics system although that might not be reliable if your system will be indoors.
Other optional hardware includes temperature controllers, growing lights, auto-feeders and similar items.
DIY aquaponics systems are designed for growing leafy greens like kale, basil, lettuce, arugula, dill and spinach, among others as they respond well to the nutrients in the fish water. They can also be grown without adding other nutritional supplements. Fruit species like strawberries, raspberries, blueberries are also grown here. It is also possible to grow cucumbers, tomatoes and zucchini, though they need supplemental fertilizers.
The most common type of fish used aquaponics systems is tilapia due to its tolerance to high stocking densities and fast growth rate; they attain maturity in 6 to 8 months. However, since they are tropical species, the water should have a temperature between 70 and 90 degrees to remain healthy.
Catfish is also ideal for the aquaponics system as it endures the cold season but only grows during warmer months. The yellow perch is another common species used in aquaponics systems. The fish is known to thrive during the winter season.
Turning fish waste into nutrients for the plants and stopping the harmful type of bacteria from developing in your system, Positive or Beneficial bacteria is absolutely essential in any aquaponics system. While it can develop naturally, you can also add it yourself to ensure success.
While it takes some solid handiwork and patience, putting everything into practice and setting up your DIY aquaponics system isn’t as hard as it looks. I’ve tried to make the whole process as straightforward as possible so roll up your sleeves, follow these 7 steps and let’s get to work!
Before we dive in, be sure to take a look at this video as it will visually show you a similar process in which they build a DIY aquaponics system very quickly. It’s much smaller and quite simple but the concept stays largely the same.
As you can see, it’s very straightforward to build one yourself. Although the one shown in the video is small and not really visually pleasing, it gives you a great idea of what you have to do and how everything works together.
Below we’ll go through all the steps that making a straightforward – but quite advanced – DIY aquaponics system. It’s one of my own personal designs and even though it works like a charm, always keep in mind that you can take shortcuts (buying containers and structures instead of re-using other items like I tend to do, for example) and customize it as well (different grow bed system, different size, etc…).
Now let’s get straight into it!
Start by using a standard 2” x 4” and plywood to construct the base and then mount the beds on the 4” x 4” posts using carriage bolts. Allow ample space between the posts for plants to mature and line the interior with a pond liner before filling it with gravel (hydro clay pebbles are also a excellent alternative).
After this, mount the beds at an angle of around five degrees to allow water to flow down and back to the fish tank. Then, cut a hole at the bottom of the raft where the PVC pipe will be fitted and drill another hole on the other side to allow water to flow back to the fish tank. Keep in mind that the top raft should be elevated and guided to the fish-food tank while the other bed is mounted beneath it.
For this project, I used a simple watering trough made of metal due to how perfectly it fits and how easy it is to get one. I cut the top to allow oxidization and constructed a wooden stand to keep the barrel from rolling over – you can easily do this yourself as well, adapting the simple stand to the shape and size of your own trough.
Then, use another barrel and cut it into half to make two small ponds at the top of the stand. This is a great little trick as it increases the surface area for the growing plants and any duckweed that appears. The trough should not be too deep; around 10 to 12 inches is a good depth for a DIY project (although you can use whatever size you want, just be sure to make everything else proportional). This depth allows for a good flow of oxygen and diffusion of thermal mass and gas.
The fish waste propels the nitrogen cycle, leading to the formation of nitrates; a crucial component for the growth of plants. However, stocking a lot of fish creates a buildup of solids and reduces the quality of water. It is purified using various filtration components that make up the raft system, the filter tanks, clarifiers and the degassing tank.
This aquaponics DIY system uses a water quality sequence that involves the removal of solid and fine particle filtration, breakdown and degassing. The clarifier is fitted to remove the solids from the water flowing from the fish tank while a filter tank is added to facilitate the bio-filtration process using a netting material that avoids anaerobic decomposition. For this part, I used a large drum with a mesh material which is great because the microbes populate the vast biological surface area of the mesh. After all of this, a degassing tank is then fitted to remove nitrogen, methane and other gases. While the degassing tank is optional, it’s extremely useful if you’re building a large aquaponics system because the gases accumulate in fishing tanks that stock lots of fish.
As a general rule of thumb for this tank, one pound of fish per ten gallons of water is the ideal proportion.
Start by drilling a hole on the higher staggered barrel to fit the one-inch PVC and allow the water to flow into the other fish-food barrel. Remember to keep the barrels slanted to allow for gravity to do its work. Then, add the fine gravel (or any other media, such as clay pebbles) to the lower gravel about six inches deep.
Cut another hole 0.75 inches upwards in the lower trough to fit the pipe that allows water to flow to the growing bed. Attach the T-fitting at the end of that pipe and another pipe across and drill holes in the cross pipe. After all of this is done, block the ends so that the water sprinkles down through the holes.
Now we’re almost done! Fill the tank with rain or pond water (you can also use tap water but you should let it age 2 weeks before using it to allow it to develop natural bacteria). Attach the pump to the fish tank and connect the hose from the pump to the fish-food barrel and switch on the pump.
The water will flow from the fish tank to the top fish-food barrel to the second fish-food trough and into the top bed through the T sprinkler. Then it will continue flowing into the lower tank then finally back into the fish tank, all clean and fresh. I know, I know, it sounds complicated but in reality it’s very easy to follow, as you’ll see for yourself.
Now’s a great time to give your system a test-run in order to check for leaks, malfunctions or any other issues that need to be fixed.
With everything set-up, fitted and tested, you’re ready to add the fish! Make sure that the water is not only sufficient but also properly adapted to your preferred fish’s requirements (temperature, age, etc…). A good rule of thumb, as mentioned previously, is to let tap water sit for about 1 to 2 weeks in order for natural bacteria to grow, which will make your fish feel right at home and ensure they’re healthy. If you can use rain water or water from a pond, that’ll be even better and requires no waiting time.
There are a lot of fish that are perfect for aquaponics – from small, decorative ones all the way up to large, edible ones – to find out the right ones for you and your system, be sure to read the best fish for aquaponics article.
Now for the exciting part – adding the plants! You can either use seeds and wait for them to grow or transplant them after they’ve already grown a bit, it’s entirely up to you. Remember to adapt the type of plant and the quantity to your system’s capabilities (both size and nutrient production from the fish).
To know which ones are perfect for your system’s size and type, be sure to read the best plants for aquaponics article.
Maintaining your DIY aquaponics system is, as expected, an absolute breeze. Depending on which route you chose to take, all you’ve got to do is either program a timer to feed the fish or do it manually yourself a few times a day.
If you’ve got lights and temperature control added, you can also program them to turn on and off at the appropriate times.
Feeding the fish the only input that the system requires of you, the rest happens automatically so all that’s left for you to do is to sit back, relax and enjoy the rewards from your hard work. Congratulations, you’ve now built your very own DIY aquaponics system like a true professional!
What a journey it has been, I truly hope that this guide has helped you! Choosing the DIY Aquaponics route might seem daunting at first but believe me, it’s worth the effort and it will reward you or years on end with healthy, delicious, fresh food and fish.
If it all seems a little bit too much work, time and patience for you then don’t worry – you’re not alone! Many people simply prefer to have the system made for them and delivered ready to use right at their doorstep. If you’re one of those people, be sure to check the best pre-built aquaponics kits you can get.
It’s been a pleasure to help you and as always, be sure to leave a comment if you need any further guidance. Thanks for reading!
Wendy Ho June 23, 2021
Hi, I need some DIY hardwarefor my aquapnice. It is so exciting that you are located in Sydney.