Introduction: Modular Hydroponics System

The inspiration for this project came when I was searching for a DIY hydroponic tower, and I was unsatisfied with all of the results. I wanted a hydroponic tower which was able to be any height, and not require the entire structure to be 3d printed.

My design is based on a single 4 inch PVC pipe, using 3d printed cups and cup holders. This design allows me to take advantage of 3d printing for mounting each of the plant cups, without having to waste material, money, and time 3d printing the rest of the tower.

The STL files needed are attached, and have also been posted to thingiverse.

Step 1: Tools & Materials

You will need the following tools:

- Hand Drill

- 2 1/8 Hole saw (Typically used for door handles)

- Misc Drill sizes

- A 3d printer with at least a 120mm print bed


- A length of 4 inch PVC Pipe. This will be the eventual height of your tower.

- A 5 Gallon Bucket for the base of the system

- A water pump. I used this one:

- Some 1/2 inch clear tubing for the pump

- 3 ft of 5/16-18 Threaded Rod

- Some 5/16-18 Nuts (6)

- Silicone Sealant. (Make sure you get a fish safe one if you are doing Aquaponics). I recommend GE Silicone 1. (Pictured)

- Some Growth Media. I am currently testing out using River Pebbles (Pictured), I will report back as to how well these work

- PLA Filament

Step 2: Print the Plant Cups and Plant Cup Holders

Begin printing the plant cups and holders as soon as possible, You will need one of each for every hole that you want, so you will need a lot of them. My tower (5ft) uses 33 of each, for a max capacity of 33 plants.

You will need to play with your print settings in order to get the plant cups to print well. I recommend if you are experiencing stringing on the plant cups to double the retract distance in your print settings.

Step 3: Drill the Pipe

This is the point where you need to decide on your plant spacing. I decided to do three plants per layer, each layer spaced 4 inches apart vertically, and every layer is offset from the ones above and below it.

I recommend the following method for drilling the holes into the pipe (for the configuration above):

1) Measure the circumference of the pipe, and mark the circumference divided into 6 equal sections. (For 4 inch pipe (4.5 inches OD), this should be about 2.35 inches)

2) Extend your markings the length of the pipe using a straight edge, lying the pipe horizontally on a flat surface.

3) Mark the vertical spacing of your plants. In each column of plants, the cups are spaced 8 inches apart. Be sure to offset every other row down 4 inches, so that the cups end up staggered, as shown in the picture.

4) Pilot drill each of the markings with a 1/8 inch drill bit.

5) Drill each hole with the hole saw.

Step 4: Mount the Cup Holders to the Tube

The cup holders can be mounted around each of the holes using silicone sealant. The sealant is placed around the rim of the cup holder, and placed on the hole. It is best to do this while the pipe is horizontal, and to only do one column at a time, to limit them slipping after being placed onto the pipe.

Be sure to use sealant liberally to avoid leaks.

Step 5: Mount the Pipe Into the Bucket

The pipe is attached to the bucket using the 5/16-18 threaded rod.

I recommend:

1) Drill the pipe with 5/16 inch through holes, so the threaded rod can pass all the way through. These should be placed with 2 each at 9, 9.5 and 10 inches from the bottom of the bucket, with the holes across from each other at the the same level.

2) Drill the bucket with 5/16 inch holes spaced around the outside of the bucket, again so that the threaded rod can pass all the way through. The holes should be placed with 2 each at 10, 10.5 and 11 inches from the bottom of the bucket (outside), with the holes across from each other at the same level.

3) Cut the Threaded rod into three 1 foot pieces.

4) Align the pipe and bucket holes (the pipe will not be touching the bottom of the bucket), and insert the threaded rod into each. This may be tight if the hole placement was not perfect.

5) Put nuts on either end of the threaded rod to hold it in place.

6) Seal around the threaded rod with silicone to avoid leaks.

Step 6: Mount the Water Diverter, Pump and the Top Adapter

Print the Top, Top Adapter, and Water Diverter

Attach the 1/2 inch clear tubing to the Water diverter, it should be a snug fit. If it is a little loose, hold it in place with silicone sealant.

Drop the tubing down through the tube, and thread it through a hole near the bottom. (you may want to drill a separate hole to do this.) Attach the tube to the pump in the bottom of the bucket.

Drill 3-6 holes for #6 screws near the top of the tower, in line with the plant cups, and attach the water diverter by screwing into the screw mounts, through the outside of the tower.

Glue the top adapter in place using silicone sealant.

The top should just sit on the top adapter ring.

Step 7: Add Grow Media, Fish, and Plants

1) Add water the the system, do not fill above the level of the threaded rods to avoid leaks.

2) Add the Grow media to each of the cups. I am using River Pebbles, you could also use clay beads or a media of your choice.

3) Add some plants that have been started either in rockwool or on cotton balls.

4) Add your fish to the system, or use hydroponics nutrients.

5) You're Done!

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