Large 24 Plant Hydroponic System From Recycled 2 Liter Soda Bottles

Introduction: Large 24 Plant Hydroponic System From Recycled 2 Liter Soda Bottles

There are 24 2L soda bottles that each hold an individual plant. Nutrient is pumped from the bottom reservoir to the top through 1/2" tubing and reduced into 1/4" tubing going into each of the top eight 2L soda bottles and is gravity drip-fed downward through remaining 16 bottles and back into the bottom nutrient reservoir..

We built this system to help people understand certain aspects of sustainability as well as providing fresh ingredients for our resident chefs and lunch for everyone else around. We incorporate this in our education curriculum at SoHa SMART. We look forward to a future of being able to grow our own food and make our own medicine as well as giving Mother Earth a break and taking responsibility .

This is a simple design and very nice to look at and listen to.

In another Instructable we will add automatization and grow lighting via LED.

*Please read entire Instructable before you begin to understand the sequence of steps and adjust for your needs.

*This system is to our specs and you can feel free to alter it to fit your size needs. Make it to fit your needs for size, indoors/outdoors, use for food production or simply ornamental. The basic guidelines and tech should get you up and running and help you understand the wonderful world of hydroponics. What you grow and individual outcomes desired will determine what you use in terms of nutrients and growing techniques.

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Step 1: Materials You Will Need...

Two 1" x 1/8" x 96" Aluminum Flatbar

Three 1-1/2" x 1/16" x 96" Aluminum Angle

Six #10 24 x 1/2" Machine Screws and Nuts

Four 1/4" x 1-1/2" Lag Screws

24: 10-12 " Zip Tie Wraps

24: 2-Liter Soda Bottles

35 Gallon + Rubbermaid Storage Container with Lid

8: Barbed Reducer Tee 1/2in To 1/4in

30 Feet FOOD GRADE Black Tubing 1/4" ID 3/8" OD

Greentrees 1/2 Inch Elbow

1/2 Inch Tubing Cap

EcoPlus 1056 GPH Submersible Pump

100 Feet FOOD GRADE Black Tubing 1/2" ID 5/8" OD

24 Hydro Flow 360 Degree 8 Stream Push-In Dripper

Hydroton Pellets

24: Rapid Rooter Plugs and Vented Germination Dome Cover

Seeds of your choice (we recommend leafy greens and edible flowers)

Basic Aquarium Pump and Airline Tubing

Basic Aquarium Air Stone

1 Basic Electrical Outlet Timer

Flat Black Spray Paint

Painters Tape

Paper & Pen


Step 2: Tools You Will Need....

Drill Press or Cordless Drill

Metal Drill Bits to match your desired fastener size

Drill Bit Sizes: 3/8", 5/8", 11/32, various.

1 1/8" Metal Hole Saw Bit


Sand Paper or a File

Razor Blade Knife or Box Citter

Tin Snips


File/Sand Paper

Scissors Razor Blade/ Knife Blade


Large and small Zip Tie's

Step 3: Draw Out Plan...

This is our plan drawn out. It is not to scale. We recommend carefully thinking about your plan and what you want to achieve. Measure the area you want to put your system and whether you will have sunlight, power outlets, access to water, etc.

Step 4: Start Seedlings...

Start seedlings 7-10 days before you plan to install. This gives you adequate time to build your system and be ready for the seedlings. We chose all edible items such as romaines, spring mix, cherry tomatoes, spicy greens, etc. as well as edible flowers. 90% of our seeds sprouted in 24 hours and were ready to plant within 7 days.

Simply follow the directions on the Rapid Rooter Plugs and Vented Germination Dome Cover packaging.

Make sure you label your different seedlings.

Step 5: Mark Aluminum for Frame...

Our Aluminum Angle and Flat Aluminum are 96" in length. These measurements are for our specs and you may have to adjust depending on your needs. The measurements can differ but the instructions can still apply.

On the 2 FLAT ALUMINUM pieces make centered holemarks at 2", 6", 36", 64" and 94". The 2" and 94" holes are for attaching frame to wall. The 6", 36" and 64" are for attaching the plant rails (Aluminum Angle) to the frame.

On the 3 ALUMINUM ANGLE make centered hole marks at 32" and 64" and only one one side. These are for attaching the plant rails to the frame.

Step 6: Mark 8 Spots for the Hole Saw...

These holes are on the 3 Aluminum Angle pieces and will be the cut-out support for each of your 2 Liter bottles.

These holes are cut out for bracket support for the 2 Liter Bottles.

Start 6" from either side and and space holes 12" apart (6", 18", 30", 42", 54", 66", 78", and 90").

There will be 8 holes per Aluminum Angle. ( 8 holes x 3 Aluminum Angles = 24 - 2 Liter Bottles

Turn the Hole Saw Bit so that it can be used as a marker to create your center where the Hole Saw's drill bit will start. Center holes with the edge in mind. A horse shoe shape is needed to support the neck of the 2 Liter Bottles. This is accomplished by cutting the hole with the hole saw and then snipping off the two edges.

Step 7: Drill and Cut Holes...

A horse shoe shape is needed to support the neck of the 2 Liter Bottles. This is accomplished by cutting the hole with the hole saw and then snipping off the two edges.

Use Metal Drill Bits to match your desired fastener size and use the same bit for the Zip Tie Holes.

Use a 1 1/8" Metal Hole Saw Bit as it fits the 2 Liter Bottles perfectly.

If you feel you need to sand/file the drilled and snipped edges, do so now.

Step 8: Assemble Frame and Fasten to Wall or Area of Choice...

Please note your orientation. We installed our hydroponics system with the Aluminum Angle facing out to the window outside. This a matter of preference and can be dependent what the area you are placing the system in allows for.

Step 9: Prepare Your 2 Liter Soda Bottles to Become Plant Holders

Remove labels from and thoroughly rinse 24 - 2 Liter Soda Bottles. Any type of 2 Liter Bottle will do. Our preference is the type without any special shape or design, just simple, long cylinders. (Example: Pepsi bottle types are our choice as Coke bottle types have an hour glass shape)

Discard caps and cut off cap band.

Step 10: Spray Paint Your 2 Liter Bottles..

Apply painters tape around the circumference 4 1/2 Inches from the bottom of each 2 Liter Bottle.

Spray paint with black spray paint. Spray paint from the tape down covering the entire bottom. Do not spray paint the top.

One good coat will do.

Follow directions on spray paint for drying times.

This is to completely block out the sun from the roots and help prevent algae.

Step 11: Cut Openings in 2 Liter Bottles...

Your plants will need room to grow and air.

Remove painters tape.

Cut a rectangular pice of paper 13" x 10".

Place paper with the 13" being the width and 10" being the height.

Use a razor knife to carefully cut out the 13" x 10" rectangular hole.

Gently remove the cut piece.

Repeat on opposite side of 2 Liter Bottle leaving two sides attaching the top and bottom.

Step 12: Drill Holes in the Bottom of 2 Liter Bottles

We used a 3/8" drill bit (you could also use an 11/32" drill bit for extra snugness) as we are using 1/4 tubing inside the bottles. (1/4 inch inside diameter and 3/8 outside diameter)

Drill directly in the center where the rough feeling area is. Drill carefully as you want as snug a fit as possible for the tubing.

Step 13: Cut and Place Your Tubing...

Time to place your water tubing.

Cut the following:

1 - 9 foot piece of 1/2" FOOD GRADE Black Tubing for top rail

1 - 12 foot piece of 1/2" FOOD GRADE Black Tubing for piece from pump to top rail

8 - 8 foot pieces of 1/4" FOOD GRADE Black Tubing for each bottle from top rail through bottles and back into the reservoir.

Step 14: Put Top Piece in and Connect to Side Piece...

Place 9 foot piece of 1/2" FOOD GRADE Black Tubing on top rail allowing 6" to over lap ON EACH SIDE. You will cap one end with the 1/2 Inch Tubing Cap as it is the end of the line.

Connect the 1/2 Inch Elbow on the side you want to connect to your reservoir pump.

Connect the 12 foot piece of 1/2" FOOD GRADE Black Tubing to the remaining side of the 1/2 Inch Elbow.

Use a zip tie on the 3 holes you drilled for the tubing on the top rail.

Use zip ties on the ends of the middle and bottom rails to hold the tubing in place as it goes up the side.

Step 15: Cut 8 Places for the Reducers...

Where each opening is (we have 8 openings) cut the 1/2 Inch Tubing and insert one of the 1/2in To 1/4in Reducer Tee. Push it in nice and snug as possible.

There are 3 sets of holes we cut on the top Aluminum Angle to tie wrap the tubing just so it stays in place.

Step 16: Cut the Eight 8 Foot Pieces of 1/4 Inch Tubing Into Segments

This is for the gravity fed 1/4 Inch Tubing going down from the top into the 2 Liter Soda Bottles.

Take the eight 8 foot pieces of 1/4" FOOD GRADE Black Tubing from step #13 and lay side by side.

Cut the following sizes from each piece:

8 Pieces that are 8" - 9"long.

16 Pieces that are approximately 24" long.

8 Pieces that are approximately 28" long. Long enough to go from the bottom of the 2 Liter Bottles, on the bottom row, back into the reservoir.

** These lengths are dependent on your specs. A good rule of thumb is that if you allow extra length, you can always trim off extra and make everything perfect later. If the tubing is too short in places it is harder to change. It is much easier to trim off extra than to replace a short piece.

Step 17: Prepare Your Drippers

If you find your Drippers aren't as snug as you like (we did) simply cut a small piece of aquarium air pum line into small pieces and place over the end of the 360 Degree 8 Stream Push-In Dripper. It will create a snug fit when you connect it to the 1/4 Inch tubing.

Step 18: Connect Drippers to the Top 8 Sections of 1/4 Inch Tubing...

Only connect the top 8 Drippers for this step and save the rest for a later step.

Step 19: Connect 8 Top 1/4 Tubing Pieces to the 8 Reducers

Remember, only 8 Drippers are needed in this step. Push them in snug.

Step 20: Prepare the Next 3 Sections of 1/4 Inch Tubing for Each of the Eight 2 Liter Bottles....

Cut a small slit on both sides of ONE END on the remaining 24 pieces of 1/4 Inch Tubing. The slit should be small and only 1/4" from the end. This has a multi purpose:

1. It prevents the 1/4 Inch Tubing from slipping through the bottom of the 2 Liter Bottles.

2. It prevents the 1/4 Inch Tubing from becoming clogged too easily allowing for good water flow.

3. It helps prevent the roots from clogging the 1/4 Inch Tubing too easily.

Only tighten the zip tie in order to form a loop at the end of the 1/4 Inch Tubing. If you tighten too much it close the tubing and prevent proper flow of water.

Step 21: Insert 1/4 Inch Tubing Into 2 Liter Bottles

Insert the end without the zip tiethrough the inside of the 2 Liter Bottle.

Pull the 1/4 Inch Tubing through from the bottom of the 2 Liter Bottle until the zip tie makes contact with the 2 Liter Bottle.

Attach a Push-In Dripper to the other end of 1/4 Inch Tubing coming down from the 2 Liter Bottle

Step 22: Attach 2 Liter Bottles to Aluminum Angle Railings...

Attach 2 Liter Bottles on top row first. (8 across)

Secure with zip ties just snug enough to hold the 1/4 Inch tubing in place but not too tight as to cut off flow. This will allow the bottle to spin but not allow it to fall out. You will want to rotate your plants often due to phototropism (the growth response of plant parts to the stimulus of light,producing a bending towards the light source)

Now connect the second row of 2 Liter Bottles. (8 across) by inserting the 1/4 Inch tubing which has the zip tie in it through the bottom of the 2 Liter Bottle and connecting a

And finally the, connect the third row of 2 Liter Bottles. (8 across)

Allow the 1/4 Inch tubing from the bottom row to hang freely as it will be inserted into the reservoir.

Step 23: Prepare Reservoir for Tubing

Drill 8 holes for the 1/4 Inch Tubing to flow back into the reservoir.

Drill 1 hole for the 1/2 Inch tubing to leave the reservoir and go up into the system.

Drill 1 hole for the air pump tubing to go into the reservoir.

Drill 1 hole big enough for the Water Pump's Electrical cord to come out of the reservoir.

Step 24: Add Water to Your Reservoir and Install Water Pump and Air Stones...

Install your water pump as directed in it's instruction manual. Use the 1/2 Inch connection to connect the 1/2 Inch Tubing.

Attach the 1/2 Inch tubing going out of the reservoir and up into the system.

Insert the 8 1/4 Inch tubes coming from the bottoms of the Eight 2 Liter Bottles

Add the Air Stone/s to your air pump hose and drop in bottom of reservoir.

Fill with purified/distilled water (or let water sit for 24 hours to let the chlorine evaporate.)

We have added a mild dose of nutrient to the water which causes the colorization. We chose BioThrive Grow for this.

Trim the 1/4 Inch Tubing to be above the waterline. the water should be allowed to drip back into the reservoir easily. If the 1/4 Inch Tubing is in the water it could possibly create a back flow and the system will not drain properly.

Cover reservoir with it's lid and make sure it is on securely

Step 25: Test the System...

Now it's time to plug in the system and test for water tightness and flow. We highly recommend you follow this step before adding plants and hydroton.

Adjust and tighten as needed.

Step 26: Prepare Your Hydroton Pellets...

Wash and prepare your Hydroton Pellets as directed on the packaging.

Step 27: Insert Hydroton Pellets in 2 Liter Bottles....

Fill the 2 Liter Bottles approximately 75% with prepared Hydroton Pellets. Leave some room for the seedlings and Rapid Rooter Plugs.

We highly recommend testing your system again now that you have added the prepared Hydroton Pellets.

Adjust and tighten as needed.

We added small zip ties to keep the 1/4 Inch tubing in place where we wanted it.

Step 28: Insert Your Seedlings...

Follow the directions on the Rapid Rooter Plug packaging and make sure you see roots. Nestle your seedling within their Rapid Rooter Plug and evenly surround with more Hydroton Pellets.

Label your 2 Liter Bottles with their corresponding seedling type.

Step 29: Program Timer....

Plug your water pump into y the timer and set your timer to your desired settings. We set ours to run for 15 minutes once an hour, every hour. 6:00-6:15, 7:00-7:15, etc.

The Air Pump should run continuously and not be on a timer.

Where you take it from here is up to you regarding feeding schedule, nutrients, organic/non organic, lighting, etc. HAVE FUN!

We will add more pics as the system matures and produces.

Step 30: Some Moonflowers From Our System During a Cold Nor'easter Day in NJ!

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    4 Discussions


    5 years ago

    -2 GENERAL ORGANIC is my favorite line of fert even tho it's NOT 100% organic BUT it is NOT a good idea to use in hydro. Your better off using 3 part General hydroponic. GO is designed for "soil/peat" even tho there's measurements for hydro on the label. Trust me when I say use GH 3part and flush for 7 days prior to harvest. Don't use anything dark/organic natured like b12 molasses floralicious plus, all great stuff but for soil my fellow gardener. Air stones and recirculating water will cause allot of growth in your lines res and regulators. In the end all that growth of live bacteria is not fert and will destroy the inside of your system by build up of unwanted bacteria. IF YOU INSIST you should flush with bleach or h2o2 for a day before adding your next cycle. Hope you have fun happy gardening!


    5 years ago

    -1 Your drain lines I'll soon clog with roots & live bacteria buildup from the bio thrive your using at fert. I suggest re thinking your drainage to using the threaded end before you have to go running for a shop vac.


    5 years ago

    Two mistakes