How to grow food, hydroponically

Photo by Indorgro

What is hydroponics?

A really curious gentleman find out some time ago that plants don’t need dirt to grow. Plants just grow in dirt because the dirt has nutrients, water, and provides a medium into which roots can grow to anchor down for support and stability. This revelation led to the insight of hydroponics, which is where plant roots grow suspended in a nutrient solution.

There are a few different varieties of hydroponics, but this demonstration will focus on just one. That being Deep Water Culture, or DWC.

simple diagram of a DWC setup

DWC is the easiest to do in my opinion AND provides great results, because it has the fewest required parts and requires the least amount of troubleshooting, if any.

Advantages with DWC hydroponics include:

  • efficient use of water and nutrients
  • quicker growth and crop yield
  • no mess from dirt

It’s not perfect though, because plants grown hydroponically can be more susceptible to mold. However, this really isn’t an issue with proper cleaning, which will be covered.

items needed:

  • H2O2 (hydrogen peroxide)
  • isopropyl alcohol
  • small paper cups
  • 5 gallon bucket X2
  • air pump, air stone, air tube
  • net pot
  • hydroton — these are expanded clay pebbles and will serve as the medium through which the roots will grow and provide support
  • nutrients
  • seeds
  • measuring cup/pipettes
  • sharpie
  • appropriate PPE (safety goggles, rubber gloves)
  • plug-in timer
  • paper towels

Cost of items

optional: grow light

I leave the grow light optional because this can be done with light from a window. It’s worth considering, because a grow light will provide more consistent results.

What Can Be Grown This Way?

  • tomatoes
  • peppers
  • sweet potato
  • pineapple
  • cucumbers

… really, most things that are typically grown in the garden can be grown hydroponically also. I’ve even successfully applied this method to tree type plants, like avocados and mangos. So, experiment with plants you like most. I’m demonstrating tomato and pepper seeds here because those are easy to find.

Fyi, this method is also commonly applied to growing cannabis so that might be where some people are familiar with it. In fact, if you search “DWC hydro” then you will likely get a few links for cannabis growing supplies.

Anyway, let’s not get distracted by that, because this can be used to grow a surprising amount of food.

Cleaning

  • equipment/tools
  • seeds
  • workspace

1. Put seeds in small paper cup. Label cups if doing several varieties. Soak seeds in a 10% solution of isopropyl alcohol diluted in tap water for 2 minutes. Then, let seeds soak in H2O2 for 15 minutes.

soak in 10% isopropyl solution and then H2O2. Photo taken by author.

2. While seeds are soaking, wipe down equipment/tools and work area with isopropyl alcohol, don’t dilute with water here. I’ll confess my work area was my bathroom. Kitchens work well, also.

3. Measure out the amount of hydroton pebbles needed for the net pot. Do this by pouring the pebbles in the net pot to be used. In this instance, I fill the pebbles to about 2 inches below the top of the net pot.

Photo by author

4. I’m using net pot that is made to fit perfectly over any regular 5 gallon bucket. While the pebbles are in the net pot and the net pot off the bucket, rinse off all the dust from the pebbles in a sink. The net pot will make this easy because it will act as a strainer while water runs through the pebbles.

Photo by author

5. After rinsing the dust off, pour the hydroton pebbles, as well as the air stones, in a second bucket (the one you won’t be using for growing) and soak them in H2O2.

6. While the seeds and pebbles are soaking in H2O2, clean the bucket that will be used for growing with isopropyl alcohol and then wipe dry.

7. After everything has been soaked and cleaned we’re ready to plant after we rinse off the pebbles one last time under a sink in the net pot.

Planting

Once the net pot and hydroton are rinsed off, place them on top of the second bucket for now.

1. Then fill up the bucket used for growing with water. Make the temperature of the water between 60–68 degrees Fahrenheit. That’s slightly cooler than room temperature, I guess.

Fill up growing bucket to roughly 3 inches from the top.

2. With the growing bucket filled up, place the air stones (which are attached to the air tubes, which are attached to the air pump) in the water. Measure the nutrients, then turn on the air pump and the bubbles will do the mixing for you.

For liquid nutrients, I use a two part solution from General Hydroponics and just follow the instructions on the bottle. I reckon that is the easiest and cheapest option.

3. Now you can place the net pot filled with clean pebbles on top of the growing bucket.

Half peppers, half tomatoes… why not!? Photo by author

4. Label the areas where you will plant specific things.

5. Then clear some pebbles to just above the waterline. Drop the seeds in spaced intervals on top of the pebbles. I like to try to have the seed slightly touching the water, but just barely.

Left uncovered and they sprouted after 36 hours. photo by author

Don’t cover them back up with pebbles. Most seeds don’t really need darkness to sprout and the pebbles can block the sprouts sometimes.

Anyway, you’re basically done. Just come back once a day and check for sprouts.

Done

Happy Urban Farming

Sprouting shouldn’t take too long, usually within a day or two for me. However, make sure the air pump is always plugged-in. It’s the oxygen pumped into the water that keeps the seeds, and later on the roots, from drowning.

The pump doesn’t need to be on 24/7, though. So I plug-in the air pump into a plug-in timer. You can use digital or mechanical, but I prefer the mechanical ones. Anyway, I set it to turn off for 15 minutes every hour. This will help save a little on electricity.

Thanks for reading.

--

--

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store