Have you heard the buzz about aquaponics yet? Ever thought about building your own aquaponics garden? Well now you can!
What Is Aquaponics?
Aquaponics is the process of growing plants and fish together in a symbiotic relationship. The entire process is driven by bacteria that convert ammonia into nitrite and then nitrate. The nitrate is then used by the plants as fertilizer. The fish receive clean oxygenated water in a recirculating environment and the plants receive water and fertilizer. There are several different methods for growing with aquaponics but all of them utilize fish, nitrifying bacteria, and plants. The most common methods include deep water culture, media bed, and my personal favorite vertical towers
Why Grow With Aquaponics?
There are several reasons why growing with aquaponics is very attractive.
- It is self-watering
- No chemical fertilizer necessary
- No weeding
- Uses significantly less water than other methods of growing plants
- Growth rates can be significantly faster
- Able to plant more densely due to less competition for nutrients
What You Need To Build Your Own Aquaponics Garden
Aquaponics might seem complicated but it really doesn’t have to be. I am going to show you how you can build your own system very inexpensively with materials anyone can source very easily. It won’t require a large collection of expensive tools and it can be assembled very quickly. This system will work both indoors or outside. I believe in using the power of the sun as much as possible, but if you choose to grow inside, plenty of options for grow lights do exist. First let’s start with the materials.
- 5 Gallon Water Jug (preferably without built in handle)
- Zip Ties
- 75 GPH Water Pump
- ¼” Irrigation line
- 8’ of 1” schedule 40 PVC
- 1 Can of Spray Paint
- 2 or 3 feeder goldfish or guppies
- Krazy Glue (or any other non –toxic super glue)
- Grow medium (gravel, expanded shale, clay balls, lava rock)
- Power Drill
- Tool to cut PVC (You can use nylon string if you don’t have a pvc cutter)
- Tool to cut water jug (I used a Jig Saw you can use almost anything though)
- Tape measure
- Permanent marker
How To Build Your Own Aquaponics Garden
Decide how big your grow bed will be. On the system shown in the pictures it is roughly 6 inches of depth. Depending on the jug you have to use, you could potentially get closer to 8 inches if you don’t have a handle built in.
Once you decide how big the grow bed will be, use the tool you selected to cut all the way around the circumference of the jug on a straight line around. You should now have two pieces of the jug. The smaller will be the grow bed and the bigger will be the fish tank.
Next take the 8’ piece of PVC (any length of 8 or more will do) and cut it into three (3) thirty inch (30’’) pieces. These will be the supports for the grow bed attached to the fish tank.
Now that you have the fish tank, grow bed, and three supports it is time to spray paint them to block as much sunlight as we can from reaching areas where water is. This will prevent algae growth in your system. I used black but you can use any color you want as long as it is opaque.
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After you are done spray painting, remove the lid on the can of spray paint as it will now be the drainage pipe for the grow bed. Take your drill and make several ½’ holes in the top for the water to drain out. Flip over your grow bed so the funneled end is facing down. The spray paint cap will cover the hole at the bottom of the grow bed. Apply the glue to the edge of the cap and press firmly into the bottom of the grow bed for a tight seal. I went around the base of the cap where it met the plastic in the grow bed afterwards just for good measure.
Now it is time to build the support system. With the fish tank on a flat level surface, use a tape measure to triangulate three equal points on the top of the fish tank. Mark these spots with a marker so you will know where to cut. You can also make a cutout from cardboard of a triangle with identical length sides if that makes it easier to visualize.
Once you have the points on the fish tank marked, place one of your 30” pieces of PVC upright and in place against the fish tank and drill two ¼” holes on either side of the PVC as close to the lip of the fish tank as possible. Once you have those two holes drilled, then drill a hole parallel to those holes in the PVC pipe so that you can secure it together with a zip tie. Repeat this process for the other two support pieces.
Now that your supports are attached at the base it is time to tie them to the grow bed at the top. Follow the same exercise with the grow bed that you did with the fish tank. Drill holes on either side of the support and zip tie the PVC to each one.
The support structure is in place and now it is time to install the pump and irrigation line. Put the ¼” irrigation in the valve extending from the pump and place the pump in the water. You can run the irrigation line parallel to the nearest PVC support and zip tie a few times to hold it in place. The irrigation line can simply rest over the top of the grow bed on the medium or you can drill a small hole in the lip of the grow bed to hold it in place.
Plug in the pump and make sure the water flows to the top. I used a 75GPH EcoPlus 66 with ¼” irrigation line so that the flow of water would not overpower the drainage from the grow bed. It is important to try out the pump and irrigation lines prior to putting in grow medium. If the water pumps in faster than the drain can let it escape then drill bigger holes in the spray can lid. When you have matched the water coming in to the water going out you are ready to put in the grow medium.
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One modification that I prefer with the system is to use the cap that came with the jug to create an irrigation line down into the fish tank to avoid splashing. Simply drill a 1/4’” hole in the lid and screw it on the down spout portion of the jug. Cut off enough ¼” Irrigation line to put into the hole you drilled so that it reaches down into the water. This allows for a seamless escape of water from grow bed to fish tank and will still provide plenty of aeration.
The final step is to put in your grow medium. You have lots of options here, just remember it needs to be inert and PH neutral. Limestone will cause problems with PH balance in your system so stay away from that. Some people use a product called hydroton that is very light and has lots of surface area. I prefer Lava Rock as it is porous and easily sourced from local stores. Fill the grow bed all the way to the very top.
You are now finished building your aquaponics garden system. Let the system run for a few days if you filled it up with tap water before adding the fish. The chlorine in the water will need a few days to off gas before it is safe for fish. You only need a small amount of fish to power the system so remember to not overstock your tank. Only a few small fish will do the job for this system.
Operating Your Aquaponics Garden (and general maintenance)
Running your system is as simple as planting your grow bed and feeding your fish. This system is ideal for growing herbs such as mint and basil or you can grow lots of wheat grass or other micro greens as well. Another function that I have used this system for is for cloning existing plants. You should clean the filter on your pump once a month or so. As your system matures, you might find the need to start understanding the chemistry of your water better. Simple test kits from API and other companies allow you to test for the four main components of water chemistry in aquaponics: PH, NH3 (Ammonia), Nitrite and Nitrate.
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You can read more in depth about all things aquaponics at my site listed below in the bio section. If you find yourself wanting to do more with aquaponics, I have a great free guide to building a scalable system that you can truly grow almost anything in, as well as grow out a good portion of edible fish.
This is a guest post by Austin Rolfs. Austin is an aquaponics enthusiast that enjoys helping other people discover how to grow plants and fish together. Find out more on his website Help With Aquaponics or on twitter @HWaquaponics.
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