How to Make "The Root" (automated Hydroponic Irrigation System)

This hydroponic system, which is made primarily from a commonly found 5-gallon paint bucket, is designed to be a cost-effective, flexible, and efficient method for growing a variety of plants in a confined space (i.e. an apartment balcony). Additionally, it can be configured to give the user automated irrigation, and feedback from multiple sensors which can be chosen arbitrarily or based on the needs of the plant.

Step 1: List of Materials

Things that you will need for this project:

1 – Plastic five gallon paint bucket

1 - 2” diameter hole saw drill bit

1 – Electric Drill

1 – pair of household scissors (for cutting tubing)

(as many as you need) – 2” diameter hydroponics slotted mesh net pot (can be found here)

1- Spool of ¼” tubing for irrigation systems (usually sold in 50 ft. increments)

(as many as you need) – Tee connectors for tubing

(as many as you need) – Adjustable dripper/pressure compensating dripper for ¼” tubing

1 – Water Pump

1 – Bit of tubing from pump to irrigation system

1 – Permanent marker

Before you start the steps for this project, it is important to consider the needs of the plant that you will be growing. How closely can you crowd them together? What are their water/nutrients demands? What are their sunlight demands? These factors will help determine the density with which they can be grown and thusly how many total holes will need to be drilled in the bucket.

Step 2: Modify the Bucket

Take the bucket and mark on the outside the points where you wish for holes to be drilled, we did this by taking a permanent marker and dotting the center of each hole, approximately at the center where the rotating shaft which attaches the bit to the drill will be. For our bucket we used a total of 24 holes, in three rows to create our system. Note: It is important to leave the holes an appropriate distance from the bottom of the bucket to allow for a sufficiently sized reservoir for water and nutrients.

Using gentle pressure drill the holes one by one, letting the high speed of the drill/bit do most of the work for you.

Test the fit of the slotted mesh net pots in the side of the bucket by sliding them in each hole. In our findings, the fit is sometimes exactly right, and other times the holes are just a bit too small for an exactly flush junction on the outside of the bucket. We used a dab of hot glue on some to ensure the net pot would stay in place.

Step 3: Building the Irrigation System

Now the irrigation system can be put together using the tubing, drippers and tee connectors. We started by first making a “trial” setup where the distance between pots is used to determine the size of tubing that will be splicing together all the tee connectors, which will have drippers descending from each one of them. In our setup, two-thirds of the net pots have dedicated drippers, with the remaining the third of them relying on the runoff from above as their primary source of irrigation, since our first and third rows are vertically aligned.

NOTE: In our findings, manually adjustable drippers (the black one shown) worked much better than the pictured "pressure compensating" drippers (the black and red ones) since we were able to dial in exactly how much water they would dispense.

Once the “trial” setup has been fit so that arc distance of the ring that is between each pair of tee connectors is just right, and the distance from the tee connector to the mesh pot has been cut these different sizes of tubing can be used as templates from which to easily and quickly cut more tubing of equal size, and uniformity in sizing is important here. Note: The drippers will actually “snap” in between the plastic in the mesh pots rather nicely, which can serve to help hold the them in place if the tubing is cut long enough.

Now you can test the fit of the irrigation system by “snapping” each dripper onto its respective net pot to hold the system in place. If some sections of tubing are too short or too long, remove those sections of tubing and recut.

Step 4: Putting It All Together

If everything fits, now is the time to attach the pump to the irrigation system and begin to run water through the whole system to check for leaks and assess how everything is working. This is a critical step in the procedure that can take considerable time to get right. For us, the primary limiting factor was finding a pump that would supply ample pressure to allow the system to drip evenly all around but would not need to exceed our 5 volt range to do so. Eventually, we landed on using a pump salvaged from a similar misting irrigation system, which occupies on of the holes in our bucket since the motor has exposed electrodes, which cannot be submerged. Additionally, we have tubing going from the intake of the pump motor to the bottom of the bucket reservoir to allow it to function in a “sump” type operation, with the discharge going into the top of the irrigation system.

Once everything is set up, put a sufficient amount of water in the bottom of the bucket and turn it on the pump (using either a series of batteries or a DC power supply at 5 volts). Check to make sure each dripper is operating as it should. Adjustable drippers will allow you to fine tune the operation of each one, pressure compensating drippers should drip at a constant rate, even with variable pressure (although this is not always the case, sometimes they are just wonky and need to be exchanged for one with a more consistent flow, hence our switch to adjustable).