Introduction: Barrelponics - Getting Started With Aquaponics

Aquaponics is the combination of aquaculture (raising aquatic animals) and hydroponics (growing plants in water, and without soil).  It's simple enough; you feed the fish, the fish feed the plants (with their waste), and the plants clean the water.  So why would anyone want to do this in the first place?  Here are some of the benefits of aquaponics:

  1. No soil means no weeding, no soil-borne diseases, and no tilling!
  2. The fish provide free fertilizer.
  3. Plants grow as much as four times faster than those grown in soil or hydroponics systems.
  4. Water waste is minimal.
  5. Grow more with less space.
  6. No land, no problem; land isn't required.
  7. Fresh fish for the taking.
  8. Year round growing is easily implemented.
Getting started with aquaponics is fun, easy, and very educational.  In this instructable I'll show you how to build, run, and maintain your system.  This system utilizes one food grade 55 gallon barrel.  This will be divided into a 30 gallon fish tank, and a 2.76 square foot grow bed; hence it is dubbed barrelponics.

Step 1: Parts and Tools

Here is what you'll need to set up your system.

1 - 55 gallon food grade barrel (check craigslist*).
1 pump (I used a 200GPH pump I bought off of Amazon).

Grow Medium (Hydroton expanded clay grow pebbles or pea gravel is preferred).
1/2" piping for pump to beds, and siphon to tank (a 10' pipe is about $2 at the hardware store).
2 - #18 o-rings
2 - #14 o-rings

Bell Siphon:
1 - 3/4" PVC pipe, 18" long.
2 - 3/4" 90° Elbow.
1 - 3/4" Male and Female threaded to slip adapter
1 - 3/4" to 1 1/2" Bell Adapter
1 - 2" PVC pipe, 8" long.
1 - 2" PVC pipe cap.
1 - 3" PVC pipe, 10" long.

anything to cut holes in plastic/PVC (I used a Dremel).

100% silicone and caulk gun

Other things you'll need:

Water Test Kit

empty soda bottle (for peeponics)

*neo71665 brought up a great point in the comments feed about buying barrels on craigslist and I wanted to expound on it here because I think its worth understanding. How do you know the barrel is indeed food grade safe? I myself buy from a person who sells food grade, and non food grade barrels of many different sizes including IBC totes. He receives them in mass quantities, cleans them up and resells them. If you can find someone who is doing this as a side business then I think you’ll find someone with a little more integrity than someone looking to make a quick buck for his personally used goods. Regardless of this I always do a smell test. Barrels used to store chemicals are a dead giveaway when you do the smell check. Most food grade barrels I’ve come across were used to store some kind of high fructose corn syrup and you can usually smell this if only faintly. Another dead giveaway is you may find dead bees inside the barrel, which have been attracted to the sweetness and got lost in the darkness (I see this often). Once you get your barrel home be sure to clean it out yourself just to be safe. If you're still worried about buying used barrels there's nothing wrong with buying them new.

Step 2: Building Your System

Once you've acquired your barrel you can make the fish tank and grow bed.  If you have a barrel like mine it will have two raised sections across the barrel separating into thirds.  Follow the top line of the topmost section to mark your cut line.  If you don't have this divider on your barrel then make your cut about 12 inches from the top.  I made a shallow cut my first time around to assure a straight cut.

After you have divided the barrel into a lower fish tank (about 2/3 of the barrel) and an upper grow bed (the remaining 1/3), clean up your cut mark with sand paper and wash out the barrel.  Then take the grow bed, flip it so the bottom of the bed is facing up, and mark the holes for the bell siphon and the intake hose.  Both pipes/hoses need to fit snug so use the actual parts for a template. Use a shallow to mark your holes on the grow bed and carefully cut them out when you're ready.  I used a Dremel for this step, but use whatever works for you.

Now prepare your fish tank by making two holes in the side.  One hole to access the fish in the front, and another in the back for the water pumps power cord.  First locate the 30 gallon mark.  On my barrel there is a line that marks this for you.  If you don't have a mark like this just measure 16 3/4" from the bottom of the fish tank, this is your mark. Mark a hole to cut out for easy access to the fish.  Make any design you want, but just be sure you leave enough room for the water surface and the bottom of the grow bed. In the back of the fish tank make a small hole so that the power cord can pass through.

Now to bringing it all together, make eight sets of small holes to tie the grow bed to the fish tank.  Drill 8 holes in the top of the fish tank (equally spaced), and 8 matching holes in the bottom lip of the grow bed.  Run eight zip ties through each set of holes to ensure a secure fit.

Once the barrel is put together you can put together all the necessary plumbing.  Screw the top and bottom of the bell siphon together making sure it fits securely through the siphon hole in the grow bed.  Make sure it's tight and that there are no gaps.  You will need a #18 o-ring to create a water tight seal here; I used two (one on each side of the grow bed).  Now take the male and female 1/2" adapters and do the same thing for the intake hole (use #14 o-rings here).  Place the water pump in the bottom of the fish tank and connect it to the bottom of the 1/2" adapter with a piece of 1/2" PVC pipe.  You may need to tinker with the pump and pipe connection.  My pump has a metric sized hole so I had to fashion an adapter out of vinyl hose and a quick connect to thread adapter.  Do what you can to make it work.

Finish the pump line by fitting 9-10" of 1/2" PVC pipe into the top of the intake adapter in the grow bed.  Then attach this to a horizontal 1/2" pipe or pipes with a 90° elbow, T-fitting, or T-fitting (this can be as long or short as you want).  I branched my pipe into two.  Cap any openings here.  You will need to drill a small hole or holes in this horizontal pipe(s) to let water out.  Start with one or two holes and check the flow rate; adjust by drilling more holes as needed.

Test your system as a whole paying special attention to the flow rate, drain rate, and any leaks; adjust where needed.  If you have any leaks in the bung holes you can use 100% silicone to seal it. If you're satisfied with everything fill the grow bed with grow media (I.e. pea gravel or clay pebbles) up to the bottom of the horizontal pump pipes.  This is necessary before cycling your system.

If you plan on using your new aquaponics system indoors I recommend painting the outside of the barrel to make it more attractive in your home.

*As a side note, it's perfectly fine to use 100% silicone over aquarium silicone (they are essentially the same).  I've used "GE Windows and Doors 100% silicone" with great results.

Step 3: Cycling Your System

Before your system is fully stocked with vegetation and fish, and in a healthy condition, you must get it it cycled.  Be patient with this as it may take three to six weeks before your system is ready.  You can add fish immediately, but it's not safe for the fish and it takes longer.

Before your system is ready to be stocked with fish it needs a healthy stock of nitrifying bacteria.  The first step to build up bacteria is adding ammonia to the system.  You can buy liquid ammonia, ammonium chloride, or provide your own (yes I went there).  By sealing your own urine in a container for a week you will have a good enough source of ammonia, but this comes with a sense of disgusting attached to it.

Once you have the ammonia follow these steps:
Add the ammonia to the fish tank, start off with a little.  Check the water with your water kit, your looking for ammonia levels of 3-5 ppm. Once this level is reached, take note of the amount of ammonia you used. Add this amount daily until the nitrite approaches 0.5 ppm.

Once nitrites appear, cut back the daily dose of ammonia you used to get it started to half.  Once nitrates appear (5 – 10 ppm), and the nitrites have zeroed out then your system is ready for fish, and has been cycled.

Step 4: Adding Plants

Once your system has been cycled and contains nitrogen feel free to add your plants.  You have 7 square feet of grow bed space so plan wisely (I've made an provided a plot map, so by all means use it).  You'll need to plan out spacing, and other things like temperature range, and ideal ph levels.  If you're having trouble identifying ideal plants for your system, consider this list of plants that have been tested in other systems:

snow peas
red salad onions
egg plant

Well I think you get the idea; you can grow a lot of great food in your aquaponics systems, and 7 square feet of grow space is a great starting point.  The list of plants that have been grown successfully in aquaponics systems is huge so if you're looking for specifics then check out this thread and post any questions there (or here in the comments feed).  You will find a great community of experienced aquaponics hobbyists that will be glad to answer any questions you have. 

Step 5: Adding Fish

When choosing fish you need to consider dietary requirements and if you can meet them, environmental requirements like temperature and tank size, and the general hardiness of the fish.  Some fish handle stress better than others.  Some can handle salt treatment and others can't.  Whatever fish you go with make sure you do your homework on that fish.  Consider some of these fish commonly used in aquaponics:

Channel Catfish
Koi or Goldfish

I think tilapia is a great choice for aquaponics because they are a very hardy fish, are fast growing, and taste good.  In a system of this size 5-6 Tilapia will do well; however you will probably need to eat one of them as they grow into adulthood. 

Step 6: Feeding Your Fish

Depending on the fish you have in your system you have several options for feed. 

Channel Catfish

Catfish are cows, they will eat and eat and eat.  Most commercial farmers will feed them them until they can't fit anymore food down their throats.  They will eat Mealworms, Crickets, red wiggler worms, and duckweed.


Bluegill's prefer a protein rich diet including worms and insects, but will eat vegetation and even its own young if food is scarce.  Consider raising Mealworms, Crickets or red wiggler worms to feed them.


In nature Tilapia eat plankton, insect larva, vegitation and fish poop.  In aquaculture they are commonly fed duckweed , a water plant that is very easy to grow yourself, which is why it's so popular (please don't feed your fish poop).

Step 7: Maintaining a Healthy Aquaponics System

Many things can go wrong with your system.  That is why it is important to watch for common problems so that corrective action can be taken to fix the problem.  To keep your system healthy and happy you'll need to watch the pH levels in your fish tank.  Check it every so often, but I don't really think it's necessary to be so concerned that you're checking several times a day; over vigilance can be just as damaging to the natural cycle in your system as not checking it.  The target to hit is 6.8 - 7.0, but anything between 6 and 7 is fine; anything below or above this should be controlled.  The ammonia in your tank will become toxic for the fish as it increases above 7, and as the pH level falls below 6 the nitrification process is hindered therefore effecting your plants.

Things that effect pH:

1. Dead fish in your tank
2. Grow medium isn't pH neutral (This is why I suggest Clay Grow Pebbles)
3. Fish Pounds exceeds plant balance (1 fish pound = 1 sq. ft. grow area)
4. Hard Water (common with tap water depending on your area)
5. Particle buildup in your grow beds (add worms to your grow beds to consume the particles)

If you find your pH level is either too high or low you can use a pH kit to fix the problem.  Alternatively you can use baking soda to raise the pH and vinegar will lower it.   If you find the problem returns you may have something in your system that you will need to change.  Go to any aquaponics discussion board, or post your problem here.  I'm confident we'll find a solution. 

Step 8: Now What?

Enjoy your new system and the food you'll produce from it, experiment a little, go big, it's all up to you.  For me I would like to produce as much food as my family eats solely from an aquaponics system.  I'm also interested in seeing how a system would run with crayfish.  If you're into Arduino you might be interested in the Arduino Ph Shield to monitor your systems vitals from your computer or smartphone.  The sky's the limit so don't hold back.

If you're interested in learning more, there's plenty of online blogs and forums devoted to the subject.  Check out the book, Aquaponic Gardening, or take an online course to get an in depth look at what you can actually do from here on out.

As always I'm glad you made it to my instructable; I hope you have enjoyed it, and please vote for me in the hydroponics and indoor gardening contest!
Hydroponics and Indoor Gardening Contest

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