When you think about hydroponics, your first thought is probably about something green, crunchy, and involving an expensive light. But people have been growing plants without soil for thousands of years—some even think it could explain the Hanging Gardens of Babylon!
But more recently, hydroponics has become huge within the sustainable gardening movement, appealing to amateurs and pros alike hoping to grow their own greens. Besides being better for the environment, hydroponic plants grow 30-50 times faster than soil plants, require less energy to find and break down food (giving them more energy to grow fruit), and have fewer problems with bugs and diseases. In general, these plants are just happier! If that sounds like something that could float your boat (and you’re feeling handy), read on and find out how to build a DIY hydroponic garden.
Considering that hydroponic farms account for some of the nation’s leading local sources of organic produce, you can imagine how sophisticated some of these setups can get. But you don’t need to turn your whole apartment (or even a whole room) into a dedicated farm space—in fact, this rig only takes up as much space as a 10-gallon storage container…because that’s what it is. Plus, this particular design only costs a fraction of what you’d pay for a store-bought starter set. You’ll have to drop some dough, but like any high-yield hobby (like brewing or baking), your initial investment in equipment will last you for months to come.
Hydroponic plants grow 30-50 times faster, require less energy, and have fewer problems with bugs and disease than soil plants.
The first thing you’ll need is a reservoir where the water can circulate all those sweet, sweet nutrients. We recommend getting a 10-gallon storage container with a lid like this one. It’s important that your container is opaque to block out the sunlight and stop algae from forming.
This size is perfect for growing around six small or medium-sized plants like lettuce, spinach, or herbs. (Tomatoes are too big, FYI.) You’ll also need some 3” slotted net pots, clay pebbles to fill them with, and a growing medium like Rockwool growing cubes with your seeds inside to top it all off. (Oh yeah…you’ll also need seeds.) Get some plant food (Dyna-Grow is basically fail-proof) and a basic pH control kit and pH tester to make sure your reservoir can support healthy nutrients. Don’t worry—we’ll get more into what all of this junk actually is and how it works soon.
The only thing missing now is the triple-threat of air: the air stone, air tube, and air pump. Air stones aerate the water (make lots of bubbles) and ensure your plants get plenty of nutrients. An air stone with a suction cup is your best bet, because it won’t move around in the container. Hook that sucker up to a basic aquarium air pump with some air tubing, and you’re on your way to gardening like a hydro pro.
Once your hydroponic garden is set up, change the water reservoir every two weeks to prevent algae and unwanted growth.
The word hydroponics actually comes from two Greek words: “hydro” means water and “ponics” means labor. That said, welcome to the “ponics” portion of this post. The first part is easy—get your seedlings started! Soak your Rockwool cubes (prepare at least 10) in water for a few minutes, stick a few seeds of your choice in each one, and care for them until they germinate.
Meanwhile, you’ll need to build a home for those netted pots. Start by cutting six 3” holes into the lid of your storage container so the bottom of your pots can go through, and the top rests flush against the lid. Next, drill a tiny hole anywhere on the side of the container (towards the top where there won’t be water) just large enough to feed your air tube through.
Now plop your air stone inside the center of the container. Attach one end of your air tube to the stone, then run the other end through the hole you just drilled outside the container. Hook that end up to your air pump, and voila! Your basic hydroponic hardware has been installed.
Next fill the container halfway up (5 gallons) with clean water and use your fancy new pH tester to measure the pH (power of hydrogen). Sounds overly dorky, but if the pH is not at the correct level, your plants won’t be able to absorb the essential goodness required for healthy growth. Ideally, you’re looking for a pH reading between 5.5 and 6.5. Your kit should include one bottle that brings the pH up and one that brings it down (think Alice in Wonderland), so use them respectively until you get a good reading. A few drops go a long way…
Read the back of your nutrients or plant food bottle to see how much you should use for 5 gallons of water, and dump it in. Turn your air pump on, and watch those bubbles go! Put the lid back on, and stick the net pots inside. Now fill your pots up halfway with washed clay pellets and stick your sprouting Rockwool cubes into the pellets.
AND THAT’S IT! Just remember to water your sprouts by hand for the first few days until the roots start to touch the water. (The splashing bubbles from the aerator actually “call” the roots down through the pot and toward the water!)
If you’re doing this indoors, you’ll need to invest in one of those fancy lamps to mimic the power of the sun, but you can keep this setup right on your porch if you don’t want to spike the electricity bill. Remember to change the water reservoir every two weeks to prevent algae and unwanted growth, but other than that, you’re good to go. Enjoy your sustainable, DIY, nutrient-rich water garden!