Our Low-Cost DIY Rain Barrel Aquaponics System

Reader Contribution by Lydia Noyes
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There’s always something new to experiment with as homesteaders, especially when it comes to one particular tool that we always seem to have excess of: rain barrels. Our Appalachian homestead runs entirely on rain water, so these rain barrels are invaluable to us, but sometimes we still have far more than we need. A few weeks ago, my husband found an innovative way to use two of them; by creating an eco friendly, self sustaining aquaponics system that fits right in our home, and with any luck, will soon be producing vibrant greens and tasty tilapia for us to snack on all year long. 

For less than the cost of a regular fish tank, we know get to raise our own fish and greens for a miniscule amount of fossil fuels. It’s an exciting step for us towards self sufficiency, and we want to share our methods with you, too.

In the past year, we’ve experimented with many different forms livestock and home-based butchering. We’ve successfully mastered raising, breeding and butchering our own meat rabbits and even raised our first pig in a pallet-constructed pig pen before butchering him on our property over the holidays, but starting an aquaponics system was decidedly more tech-involved. Nonetheless, we think it was well worth the effort and should benefit our homestead for years to come.

What Is Aquaponics?

By definition, an aquaponics system is a blend of aquaculture (the cultivation of fish) and hydroponics (growing plants in water instead of soil). The benefit of combining these two ideas is that plants and fish actually help each other thrive. Fish poop and uneaten food scraps infuse the water with nutrients, which act as a natural fertilizer for the plants growing above. In the same way, the work of the pump in the system aerates the water for the fish, keeping them healthy. It’s a closed loop system where waste is constantly recirculated for the benefit of all organisms.

There are plenty of professional aquaponics systems on the market today, but none can come as cheaply as our simple rain barrel model. Best of all, our system has a capacity of over twenty full grown tilapia, ensuring that it’s well worth the space it takes up in the pantry.

How to Build Your Own Rain Barrel Aquaponics System

The first part of any homestead projecting is gather up the tools and supplies you need (or pilfering them from other projects like we did with our rabbit lawn mower). In order to make this project you will need the following supplies:

– Two food-grade 55 gallon barrels, one whole,  one with at least 12″ of bottom intact
– 1/4″ by (1/2″ long) stainless steel carriage bolts
– Stainless steel washers and nuts
– Piece of plexiglass (if you want a peep hole)
– Aquarium safe silicon
– Small aquarium or pond pump
– PVC scrap
– Two 1/2″ PVC male adapters and two female adapters
– A working bell siphon and 1/2” ball valve

Steps for Success

1. First, remove the top from one of your barrels in order to create a twelve inch grow space for your plants on top of the aquaponics system. In the second barrel, cut out two squares in the top third to serve as access points to get at your fish. A drill and jig saw work best for this step.

2. Next, cut out the plexiglass by marking the shape you want and putting masking tape on the bottom of the glass where you plan to make the cuts, in order to prevent the plastic from fusing back together after it gets cut.

3. Once you have your plexiglass, mark out where the bolt holes will go (about 2” apart) with a sharpie and drill out the holes. (Apply as little pressure as possible to the plexiglass). Heat the plexiglass in the low heated oven for about five minutes in order to make it easy to bend, and place it inside your newly cut barrel, leaving it in place for ten minutes.

4. Now, using the plexiglass as a guide, drill the middle holes on the window and insert bolts from the inside out, adding a washer and nut in the process. Continue drilling from the middle out, securing the bolts as you go.

5. Once the bolts are in place, seal them with a bead of silicon to make the system watertight. Make sure each bolt is finger tight before going over them all with a wrench as well. The tighter you can get each bolt the more water tight your barrel will be, so take your time!

6. To form the grow bed, take the bottom of your second barrel and cut two holes in the bottom, one in the middle (the drain) and one closer to the side (to feed the pump). Tap each hole with a 3/4” tap, and thread in the male adapter from the top, adding the female adapter to the underside.

7. Set up the bell siphon, media guard, and inlet pipe in the middle hole of the bed, and attach the pump to the underside so that it pumps water from the bottom barrel to the grow bed before draining out the middle.

8. Fill the grow bed with gravel or expanded clay, start your plants and add some fish to the base. Your system is ready to go.

Note: The original instructions we followed can be found at Instructables.com.

We couldn’t be happier with how well our rain barrel aquaponics system turned out, and look forward to it lowering our food footprint for years to come. If you choose to make an rain barrel aquaponics system of your own, please contact me about your experience, because I’d love to hear about it!

Lydia Noyes is an Appalachian homesteader and full-time freelance writer whose writing on natural living and sustainability can be found all over the web, including her posts for MOTHER EARTH NEWS here. You can connect with Lydia at her personal blog and on Instagram.

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