What a Hydroponic Garden is and How to Make One

Wouldn’t it be great to have fresh herbs all year round no matter the weather? In this post I will be explaining what a hydroponic garden is and how to make one of your own so you can have fresh herbs readily available all the time.

But first, what a hydroponic garden is and why would you want one? Simply put, it’s a garden you can use all year round inside your home. Unlike a traditional soil garden, the roots of plants in a hydroponic garden get their vitamins by soaking them up through the water they are submerged in. Thereby making them ideal for growing things indoors. That means you won’t have to run out to the grocery store for those sweet green herbs ever again! And finally, it’s wicked fast! Check this out:

Picture taken April 29, 2020.
Picture taken May 4, 2020.

This post will be a high-level overview of how you can build a small hydroponic garden, and is intended to give absolute beginners all of the information they need to be seriously successful.

A side note: You can buy a fully built off-the-shelf system, but you will have less control over it, and you will spend much more for less.

Also, keep in mind that everyone will arrive at their own way of doing things, and making your garden work in your space will require you to get your creative juices flowing. In fact, since we just moved into our new space in Maine, I’ll be tending to my own garden right alongside you all, and hopefully we can also learn some things together. If you come up with some brilliant way of your own to make things work and want to share with the community, please feel free to to share.

Make your own hydroponic herb garden!

What You’ll Need.


A Small Container

To begin with, you will need a container for water. It needs a lid as well for the baskets that the plants will go in. I use this one from Amazon, which comes with the holes already cut out of the lid. I purchased it several years ago before I owned my own tools and drill, so I preferred the convenience of this system. However, if you have the tools (drill, Xacto knife, etc.), you can simply purchase a small tote with a lid and make your own holes. I did this with my larger aeroponic system, and it was very simple.

Container with pre-cut holes, baskets, and easy to lift lid. The green things are blocking out unwanted light preventing algae from growing.

Air Pump, Hose, and Air Stone

Use a pump like those meant for aquariums. I use the one I’ve listed here. It’s reliable and also has rubber feet, which make it very quiet. You will need an Air Stone (a.k.a bubbler that sits below the surface of the water) and hose to connect up with the aquarium pump. You can see the links below for more information on the specific components. Quick tip on Air Stones: I’ve had one break after being shipped to my place, so try to order one encapsulated in plastic, such as the one I’ve linked to, or go buy one in person.

Blue Air Stone at Bottom of Tank
Air Pump and Hose. Right Side Blocked Off with Hose and Zip-tie.

A Light

Choose a light that fits in the space you have. It should produce no less than 6000K color.

Plants such as herbs grow best with a light that produces a white color closest to actual daylight (~6000K on the Kelvin Scale). See the example to the right. Plants grown under a white light are not as capable of producing fruit as those grown under a more purplish spectrum of light.

It doesn’t matter if they’re LED or fluorescent bulbs. I was able to find a shorter fluorescent one that fit my space from Home Depot. The fluorescent bulbs you’ll want are number T5. Many fluorescent lights out there are really long so make sure that you choose one that fits your environs. Also, LEDs are more expensive up front, but last longer and save money in the long run if you plan to use them often.


Rock wool

This is the stuff that holds your seeds in place so that you can then put them in the mesh cups that go into the main water container. It helps wick nutrients to the seeds when the are first started. Here’s some on Amazon.


Nutrients

I prefer to use the powdered version of MaxiGro in my systems. It has lasted me several years now and comes in a small, resealable container. Check out my previous post here to see the basil that was grown using MaxiGro and the system being laid out on this post!


Nutrient Meter and pH Meter

Without knowing how much of a nutrient powder or solution you’ve added it will be extremely difficult to know if you’ve added enough, which can impact the growth of your plants. On the other hand, adding too much could cause the the roots in your system to “burn,” turning from a healthy white to a browner hue.

Using the meters is easy. To use the Nutrient meter (on left) turn it on, make sure it’s reading in ppm, place the probe end into the water and wait until the reading is stable. That’s it, you’ve read the nutrient level of your garden. The nutrient meter can usually spit out readings in a few different units, but ppm and EC are the most widely used.

Nutrient meter left, pH meter right.
Nutrient meter being used to measure ppm of water in container.

To use the pH meter, turn it on and place the probe end into the water. Next, wait for a steady reading.

Why use a pH Meter

I will explain the importance of pH in a separate post. If you plan to measure and adjust the pH you will need some alkaline and acidic buffer solutions such as these. You add to the container of water in small amounts, measuring the pH after a few minutes. Do this until the water in your system is what you’d like it to be. A pH of around 7.0 is a good start for most plants. Water sources from taps tend to vary a lot from place to place in the U.S.. I’ve had water measure as basic as 9.0 in Boston and as neutral as 7.2 in New York City. So it is worth knowing what you’re working with by using one of these clever meters.

pH Meter in action. Check out the roots and the air stone with hose passing through container!

A Rack or Shelf

You will need a way to hang your light above your garden. This small rack here is a great option. But maybe you have a rack or shelf you could repurpose with some screw in hooks. Get creative!

Here @lmcookin and I have stacked our cook books on top of our rack for herbs!

You can spiff up the cords by tying them to the poles using wire ties like the ones that come on loaves of bread.

Another option, would be using a large upside-down cardboard box with the front cut out and some holes cut into the ceiling.



(Optional) Automatic Timer

Using an auto timer will ensure you’re always delivering enough light to your plants. But you can also turn the light and pump off and on when it’s time to, so that you can reduce your electricity consumption. Seedlings need about 14-18 hours of light per day.



Assembly

Find a location for the container and light. Set up your light so it can be adjusted up or down (I use small chains to hang my light). Seedlings need the light to be about an inch from the surface of the container. After they’ve sprouted, you should raise the light higher as they grow taller.

Fill your reservoir with the coldest water you can. Colder water has fewer particles in it than hot water. Add several teaspoons of nutrient powder or fluid to your container and measure the waters ppm using the nutrient meter (note: it make take several minutes for the nutrients to fully disperse). To start out, it should be about 500ppm.

Add the baskets to the lid of your reservoir. When your herbs grow tall the baskets like to pull out sometimes so I’ve drilled holes in my container and added some zip-ties to hold the baskets down.

Attach one end of your hose to your air stone. Cut to a length to where your air pump will be sitting. Feed the other end through a small hole in the corner of your container and connect it to the air pump.

Program your automatic timer to run for 14 to 18 hrs a day if you’ve got one.

Plug in your lights and pump.

Cut the rock wool down to a single cell. Next, cut the rock wool cell down it’s side and spread it open. Then, add a few seeds of your favorite herbs to each. Stuff the rock wool into the baskets.

Sit back, relax, read a book, do some yoga. You are now the proud owner of indoor herb garden that works for you. 😀

Make sure to monitor the nutrient levels of the water semi-regularly. If you don’t have a way to measure and adjust the pH on a weekly basis, just dump the water out and start anew on a biweekly or monthly basis.

Thank you for reading my friends. Hopefully you now have a better understanding of what a hydroponic garden is and how to make one.

Have fresh basil all year-round! Picture taken and end of this post’s creation May 4th, 2020

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