DESKTOP HYDROPONIC TOWER

Farming is one of the most important thing in this world - every human being rely on food produced from farming. But conventional farming requires a large amount of water and with climate change and natural calamities, farming can become challenging.

As a result, democratized farming, growing food for own consumption and micro farming is gaining popularity. And hydroponic system - the system of growing vegetables without the use of conventional media (like soil) and relying on nutrient rich water, is gaining popularity among home based growers. And hydroponic systems can use up to 10 times lesser water than using conventional growing media.

Vertical farming is a relatively new way of growing to minimize the footprint but can still require a decent amount of space.

(Source: Google Image)

Commercially available vertical gardening setups can cost a lot of money and for that reason, I decided to make this instructables where I show how you can make your own desktop vertical garden and get familiarized with the system. You can either use this as a stepping stone for getting into larger system or simply use it to grow smaller plants like herbs and microgreens.

Here's the list of things you will need to complete this project:

1. 3D printer (to print the pieces).
2. Reservoir container (Ikea BINTJE or Ikea MUSKOT).
3. Small submersible pump (I have used 55 gph fixed flow aquarium pump but I would suggest something smaller or adjustable with about 2ft. of head pressure like Hydrofarm AAPW40).
4. 5/8" Clear vinyl tube.
5. x2 timer/smart outlets (like Kasa smart plug).
6. x6 2" rockwools (you can also use clay pebbles).
7. Seeds (herbs or microgreen - use small plants since the setup is small).
8. Nutrient solution (a lot of options available - more on this in later section).
9. Hot glue (suggested).
10. Ziptie (optional).
11. Light - natural (if you can keep the tower close to window) or lamp.

The idea behind a hydroponic tower is fairly simple. There's a reservoir of nutrient solution and a pump sits in it. The pump pumps the nutrient solution up to the top of the tower and then the solution trickles down into the reservoir while feeding the roots of the plants.

The design intent of this project was to keep it small so that it can be kept on a desk and can be easily maintained.

I chose an Ikea BINTJE pot because it's very inexpensive, water tight and small in size - perfect footprint for a desk.

For the body, I chose 3D printing because of the design freedom that additive manufacturing provides. Similar tower can be made out of PVC pipes too so if you do not have a 3D printer, gain some inspiration from online blogs/forums where people make hydroponic towers using PVC pipes.

For the containers that holds the plants, I chose to design my own with tabs onto which, the name of the plant can be written down. You can also use 2" net cups that are available and very inexpensive.

(Source: Google Image)

Although I have used BINTJE pot, the design can be used for MUSKOT pots too. In fact, MUSKOT pot would be more aesthetically pleasing and since it is slightly larger, it will hold more nutrient solution and thus, will require less refill. I have added lid design for both MUSKOT and BINTJE pot.

(Source: Ikea BINTJE webpage)

(Source: Ikea MUSKOT webpage)

P.S. The MUSKOT pot lid was designed based off of Ikea's drawing and hasn't been tested but (assuming Ikea's drawing is correct), it should work when printed in a properly tuned 3D printer.

For the pump, I salvaged a tiny submersible aquarium pump with a 55gph rating. This is a bit more than what I should have used (a 20-30gph would be more suitable). As suggested in the previous section, try to source a pump that has adjustable flow. Too much flow can cause water to slash out underneath the lid. You can always put watertight tap around the lid as a gasket to prevent any water spill.

All the prints are done on my Ender 3 pro. The tolerances can be pretty tight for the joints so a well tuned 3D printer is required.

Here are the parameters:

Material: PLA
Infill: 15%
Shells: 3
Speed: [depends on your printer]
Temperatures: [depends on your filament]

Overall, the prints took me around 50 hours but this is very subjective to your 3D printer and how fast you print. I prefer printing slowly.

All the files have been shared.

Print quantities:
x1 BINTJE/MUSKOT pot lid
x1 BODY
x1 TOP CAP
x1 WATER SPRAY
x6 NETCUP

After all the parts are 3D printed, it is time to assemble the whole thing.

Line up the four tabs on the lid with the four groves of the body. Push in the lid and twist it clockwise to lock it in place.

Put a bit of hot glue around the bottom of the lid (where the lid and the body join) to create a watertight seal.

Connect the tube to the motor. The motor that I used already have a bit of narrower pipe so I kept it as is and pushed in the 5/8" clear tube.

Pass the tube through the bottom of the body (through the hole in the center).

Pull the cable out from the top. Make sure you have about 2-1/2" of tube left.

Push the tube into the bottom of the water sprayer. If you want, you can put a ziptie around the tube to make a more reliable connection.

Line up the tabs on the water sprayer with the groove at the top of the body, push in the sprayer and rotate counter clockwise to lock it in place.

Line up the tabs on the top cap with the grooves on the top of the water sprayer and, push in the top cap and rotate it counter clockwise to lock it in place.

Put the lid onto the pot to make sure that the motor is sitting nicely at the bottom of the pot and the length of the tube is fine. If needed, cut the tube to make sure motor is sitting at the bottom of the pot and the tube is straight.

Pass the cable through the cut out in the lid.

Time to fill up the reservoir (pot) with nutrient solution.

Since there is no soil in hydroponic system, the plant has to get the required nutrients from something so the nutrients are mixed with water. This is a very efficient way of feeding nutrient to the plants.

There are a lot of nutrients available in the market - if you do a bit of research online, you will find various brands but General Hydroponics & Masterblend are probably the two most popular ones available in the market. There are many great resources online so I will not go into too much detail.

Before you pour the nutrient solution into the water, you need to pH adjust the water to make sure that the pH of the water is between 5.5 - 6.5. You can do this in many different ways and hydroponics blogs/resources is you best bet to find more about it.

I use General Hydroponics because it's easily available where I live and is relatively inexpensive.

Make sure you follow the mixing instructions of the nutrient solution. For example, General Hydroponics has a sequence of mixing the three solutions in order for the nutrients to not bind/precipitate. The water may change its color after mixing (depending on the solution).

Put the body assembly with the pump submerged into the solution and you are ready to put some plants in it!

Do a test run by running the pump to make sure there is no leak and the solution is cycling properly.

or hydroponics, the two most popular mediums are rockwool and clay pebbles. I prefer 2" rockwool because they are cheap and easy to work with.

You have to germinate the seeds before putting the rockwool into netcups (printed/bought). There are great youtube videos and blogs that shows how to start seeds in rockwool/clay pebbles before putting them into hydroponics system.

I already had six germinated seedlings so I decided to use those in the 3D printed netcups.

Push the rockwools with the seedlings carefully into the netcups, making sure that you are not destroying any roots (or keep it at minimal). You can push the rockwool all the way to the bottom or leave a little bit of space too.

You can also buy 2" netcups that are available in hydroponic stores or online and use them instead of the 3D printed ones.

But the 3D printed ones are nicer, the sit better into the tower and you can put labels to remember what plant you have in there.

Almost done! Now you have to automate the pump so that it is not running 24/7 because that is not necessary and you may actually end up hurting the plants. Also, if you cannot keep it in a well lit area, you will have to supplement light to the plants. I prefer using a nice and bright LED bulb in a lamp (regular 5000-6000K lamps will work, you don't need to use lights marketed as grow lights).

For pump and light, you will need two separate smart plug/programmable plug. Pumps will need to run intermittently (e.g. 15mins on, 1 hour off) while light will need to be on for 12+ hours (some people go as high as 16 hours) continuously.

I like using TP-Link Kasa mini smart outlets because they are inexpensive and not bulky like many other programable plugs

Program your plugs, connect your motor and light, put some labels and you are all done!

Enjoy the marvel of plants being grown out of water (with nutrient) only!