DIY Aquaponics System – 20 Gallon Aquarium Conversion

DIY Aquaponics System: Converting a 20 gallon aquarium into an aquaponics system.

This is my first attempt at a DIY Aquaponics System step-by-step explanation, so please bare with me if it isn’t explained as well as it could be.  I would really appreciate any and all feedback on how to make it more succinct, explain the process better, if any part didn’t make sense or if I totally missed something, so I can improve my subsequent DIY Aquaponics tutorials.

Materials You Will Need:

  1. 20 gallon glass aquarium
  2. Water pump
  3. Aerator
  4. Aquarium light
  5. Grow light
  6. Expanded clay pebbles
  7. Plastic seedling tray
  8. Tubing for aerator and water pump
  9. Aquarium gravel
  10. Seedlings
  11. Fish
  12. Aquatic plants
  13. Fish food
  14. Water tester
  15. Wood
DIY Aquaponics Components

DIY Aquaponics Components

Expanded Clay Pebbles

Expanded Clay Pebbles

Building Process

Step 1:  Build the Aquarium Cover

  • Cut a piece of plywood so it fits onto the top of the aquarium.  It should rest on the edges that protrude inward and are depressed about a half inch below the very top of the aquarium.
  • Cut two openings in the back left and right corners of the cover to allow the chords from the pump and heater to exit the aquarium.  These holes will also allow the water that is pumped into the grow bed to drain back into the aquarium so make sure they are large enough for the water to flow back through the cover without contacting it.
  • Cut an opening in the front center of the cover so you can feed the fish.
DIY Aquaponics: Aquarium Cover

DIY Aquaponics: Aquarium Cover

  • Drill a hole in the aquarium cover to allow the tubing from the aerator to pass through it and enter the aquarium.
  • Coat the cover with a sealant so it doesn’t rot.  You can use aquarium grade silicone to seal it.
DIY Aquaponics: Aerator Tubing Entrance

DIY Aquaponics: Aerator Tubing Entrance

Step 2:  Build the Grow Bed

  • Build a box to contain the plastic seedling tray (for aesthetics).
  • Coat all wood with a sealant (aquarium grade silicone works) so the wood wont rot if contacted by water.
  • Drill holes in the back corners of the box and seedling tray to allow the water to drain back into the aquarium.
DIY Aquaponics: Grow Bed Drainage Hole

DIY Aquaponics: Grow Bed Drainage Hole

  • Place the finished seedling tray into the wooden box.
DIY Aquaponics: Grow Bed

DIY Aquaponics: Grow Bed


Step 3: Build the Frame.

  •  Use 1/2 inch dowels and 2×4’s to build the frame for this aquaponics system.  (anything that achieves the same purpose can also be used)
  • Build a base that surrounds the bottom of the aquarium.  It will rest on the same thing that the aquarium rests on.  Cut the 2×4’s into blocks about 2″X2″ for the four corners of the base.  Then drill holes into the blocks so that will allow the insertion of the dowels into these holes to connect the base of the frame.  Make sure the dowels fit into these holes tightly so the frame doesn’t fall apart.
  • Cut the 2X4 into two pieces that are 4′ tall.  Next, drill a hole through the bottom of the 2X4 at a height that the dowel that connects the base of the frame together can slide all the way through the 2X4 attaching it to the base (make sure the 2X4 rests on the same surface the base does so it is stable).  Then, drill pairs of holes through both 2X4’s starting 6 inches above the fish tank’s top and ending an inch bellow the top of the 2X4’s at 4-6 inch intervals.  The sets of drill holes at the top of the 2X4’s allows the 2X4’s to be connected to one another by two dowels, thus securing and completing the frame.
  • The drill holes bellow the top holes that connect the frame will be used to attach the light and allow it to move up and down vertically, so you can adjust to the height of your growing plants!
DIY Aquaponics Frame

DIY Aquaponics Frame


Putting It Together

Step 1: Setup aerator.

  •  Pull the tubing from the aerator through the drill hole in the aquarium cover.
  • Attach the end of the tubing to an air stone.  Do not put the air stone in the tank or the cover on yet, leave it to the side.
DIY Aquaponics: Aerator Setup

DIY Aquaponics: Aerator Setup

Step 2: Fill tank with gravel and environment enhancers.

  •  Fill the bottom of the aquarium with substrate, gravel and any other environment enhancers you wish to use.

Step 3: Setup the pump and the aquarium heater.

  • Attach enough 1/4 inch tubing to the water pump to allow the tubing to reach the grow bed.
  • Attach the pump to the left side of the aquarium with its suction cups.

Step 4: Fill tank with water and (optional – plant aquatic plants ).

  •  Place a plate on the gravel or whatever you put on the bottom of your tank so that when you fill it with water it doesn’t move.
  • Fill the tank up with water and plant whatever aquatic plants you wish to have in you’re aquaponics system.

Step 5: Put the aquarium lid on and run chords and tubing through the holes in the cover and out of the aquarium.

  • Place the air stone that is attached to the aerator at the bottom of the aquarium.
  • Pull the chords and tubing from the heater and water pump the the back corners of the aquarium where the holes in the cover are so that the cover can be placed on top of the aquarium.

Step 6: Setup frame around the aquarium.

  •  Put the frame together and make sure it is secure.
DIY Aquaponics Frame

Step 7: Thoroughly clean expanded clay pebbles by running clean water over them until the water running off of the pebbles is completely clean and clear.

Cleaning Expanded Clay Pebbles

Cleaning Expanded Clay Pebbles

Step 8: Fill the grow bed with the cleaned pebbles.

Step 9: Clean all dirt off the seedlings’ roots.

Cleaning Seedling's Roots

Cleaning Seedling’s Roots

Step 10: Plant the seedlings in the grow bed making sure the roots are all the way under the expanded clay pebbles.

Step 11: Place the grow bed on top of the aquarium cover.

DIY Aquaponics

DIY Aquaponics

Step 12: Attach water pump tubing so the outflow is going into the grow bed.

DIY Aquaponics: Attaching the Water Pump

DIY Aquaponics: Attaching the Water Pump

Step 13: Attach the grow light to the frame at an appropriate height above the seedlings.

DIY Aquaponics: Attaching the Grow Light

DIY Aquaponics: Attaching the Grow Light

Step 14: Run the water pump and aerator for a couple weeks to establish bacterial colonies that will filter the toxins out of the water for the fish.

Step 15: Add fish to the aquarium after the bacterial colonies are properly established.

DIY Aquaponics: The Finished Aquaponics System

DIY Aquaponics: The Finished Aquaponics System

I hope this helped, thank you for reading.

New 40 Gallon Tank

I was recently given a 40 gallon fish tank equipped with a 55W, 2000L/h pump, a Odyssea 24″ T5 light, and a 200W thermometer.  The tank itself is filled with beautiful black sand and an aquatic plant centerpiece (I do not know the name of the plant, please comment if you do).  It also came with a gorgeous Shukin goldfish who goes by the name of Bubba.  I posted some pictures bellow for your enjoyment!

Bubba in a 40 Gallon Tank

Bubba in a 40 Gallon Tank

Bubba in a 40 Gallon Tank

Bubba in a 40 Gallon Tank








2000L/h Filtering Pump

2000L/h Filtering Pump


20 Gallon Aquaponics Grows Plants

Here are some pictures documenting the growth of the plants most recently grown in my 20 gallon aquaponic system.  The pictures are dated to make it easy to see the speed at which the plants grew in the aquaponic system.

The plants in the system are as follows: the plant in the front center space is edamame;  in the back center is a tomato;  in the back right is a bayleaf tree; and the plant in the front right of the tray is a small rosemary plant.

March 17th, 2014


March 26th, 2014


April 22nd, 2014


May 6th, 2014


As one can see, in just two months, the tomato plant thrived in the aquaponic system better than any other plant I have grown thus far.  After this picture was taken, it continued to grow explosively until it was overwhelming the living-room space, and I had to take it out.  The next time tomatoes are grown in this system, I will make sure to build a lattice to direct and contain the growth of the plant(s).  My hope is that these pictures will motivate fellow sustainable entrepreneurs!

What is Aquaponics?

Aquaponics is the combination of aquaculture (raising fish) and hydroponics (growing plants without soil). Aquaponics combines these two techniques in a recirculating, closed loop system that grows fish and plants simultaneously. Since aquaponics is a closed loop system, no resource is wasted, making it more efficient than aquaculture, hydroponics, and traditional agriculture.

How Aquaponics Works

How Aquaponics Works

How does it Work?

In an aquaponics system there are two components: a fish tank and a grow bed.

When the fish are fed, they produce waste in the water of the fish tank. This water containing fish waste is then pumped from the tank to a grow bed. Bacteria that naturally occur in the grow bed convert the waste into plant fertilizer. The plants in the grow bed then use the fertilizer to grow, simultaneously filtering the water of its contents. The clean water then drains or is pumped from the grow bed back into the fish tank. Then the cycle repeats.


Additional information can be found on these sites:

Santa Barbara to Seattle

As operations were just starting to come together in Santa Barbara, California, I had to move locations to Seattle, Washington and leave behind all tangible progress towards becoming sustainable.  Before I left, I gave all of my sustainable creations:  the planter boxes full of vegetables, the aquaponics system, and the fish tank, to my neighbors.  Although it was disappointing to give away all of the tangible progress I made, the intangible progress, what I learned during the process, is what’s most important.

Planter Boxes of Vegetables

Goodbye Planter Boxes of Vegetables

I learned that building planter boxes is easy, and becoming sustainable is hard.  The main obstacle I encountered when growing vegetables was a lack of space.  Spacial constraints prohibited me from growing enough food to revolutionize my diet.  I was, however, able to grow enough food among the planter boxes to noticeably reduce the amount of vegetables I needed to buy from the store.  

In my experiment, the plants that were most productive were the foliage plants.  By foliage plants, I mean the plants that have edible leaves and/or stems, opposed to flowering plants where you have to wait for the plant to grow a flower and wait for that flower to be pollinated before anything edible starts growing.  Romaine lettuce, red lettuce, and sweet peas were the three plants that yielded enough in the small space available to eat consistently.  The Romaine lettuce and red lettuce (foliage plants) produced substantially more than the sweet peas (flowering plant).  So, if you are a college student trying to grow vegetables with limited available space I would highly recommend growing Romaine lettuce and red lettuce, and keep sweet peas in mind.

There are also some simple ideas you can use to expand the space available for growing.  Rather than being limited to growing everything in garden beds on the ground, consider these options:  you can build pots to place on your window or hang; you can build planter boxes where there is no garden already; you can build raised garden beds if the ground doesn’t get enough light or you just want easier access to the plants without the hassle of bending over.  When using these ideas, or any of your own, keep in mind that vertical orientation can save a lot of space.  Vertical orientation is essentially using the vertical space in your garden rather than just the horizontal space.  For example, you can arrange multiple planter boxes, pots, or whatever you’re using, in a vertical stack, in such a way as to let light shine on all the plants in the top planter box while simultaneously allowing light to reach all of the subsequent planter boxes underneath.  There are many examples online of gardens utilizing vertical orientation.

Aquaponics System

Goodbye Aquaponics 1.0

When you don’t have the ability to garden outside, aquaponics is a cool way to do it inside.  The first aquaponics system I built worked better than I ever imagined.  The plants in the aquaponics system grew about twice as fast as the plants outside.  The plants that thrived most in the system were melon plants and tomato plants.  Before I left Santa Barbara, the melon and tomato plants were growing one to two inches per day!  Although the original aquaponics system had to be abandoned, my goal of creating a more intelligent system is still underway.   The Aquaponics 2.0, a system of similar design to my first system, is currently running in my house, growing a cherry tomato plant, an edamame plant, a rosemary plant, and a bay leaf plant.  All is going well in the new system, but there is always room for improvement.

Fish Tank

Goodbye Fish Tank

Goodbye, beautiful Santa Barbara.  It’s been fun.  Hello, Seattle.