By: Matthew Horgan
Ever have the urge to grow something green? Since most of us live in cities, access to space to grow plants is practically non-existent, and soils are often contaminated with heavy metals and other industrial pollutants. Despite these conditions, people are using creative hydroponic growing techniques that do not rely on traditional methods of growing food.
Hydroponic systems are unique in that they do not use soil to grow plants. Instead, nutrients are delivered to plants using a nutrient-rich water, also called nutrient solution.
Recently, I created a container deep water culture hydroponic system by re-purposing an old plastic storage tote. In deep water culture (DWC) systems, plants sit directly in nutrient-rich water, and an air pump & air stone keep the water from stagnating by blowing bubbles.
It was super easy, and I’ve outlined the steps here so that you can construct your own DWC hydroponic herb garden in your home today!
Step 1: Gather your materials (see links at end of post):
- Storage Tote
- 2″-3″ Hole Saw Drill Attachment
- Net Pots (2″, 3″)
- Coco Coir Plugs
- Dry Nutrients Part A and B for Lettuce (also good for herbs)
- Digital EC Meter & pH Meter
- Measuring Spoons
- Air Pump
- Air Stone
- Herb & Lettuce Seeds
Step 2: Drill holes into the lid of your storage tote.
You can drill as many holes as you think will fit the size of your tote’s lid. I went with 13 holes after spacing out each plant site about 3″ apart from each other. When complete, remove all plastic scraps and debris by rinsing the tote out.
Step 3: Fill the container nearly to the top with tap water & add dry nutrients.
A simple method for making nutrient solution is to take a quart-sized container (like an old Chinese food container) and fill it nearly to the top with tap water (you can use the water that is already in your tote.) Then, add a teaspoon of part A and a teaspoon of part B of the dry nutrients. Add nutrient solution to your reservoir where your plants live, and measure the electrical conductivity (EC). You want the EC to measure 900-1300 ppm to grow most herbs and lettuce, and you can add another teaspoon of each part A & B as necessary to reach the desired EC level. After each harvest, check your EC and add nutrients & water when necessary to maintain the 900-1300 ppm range.
Step 4: Install the air pump and air stone.
The air pump attaches to the air stone via a small plastic tube (usually provided). Place the air stone in the nutrient solution and the air pump at a higher elevation than the level of the water in your deep water culture system (to prevent a siphoning of water out of your system).
Step 5: Insert the net pots into the holes you cut for each plant site.
You want the bottom of the net pots to be submerged in nutrient solution, so push the net pots in and then add a coco coir plug to each plant site.
Step 6: Plant your herb and lettuce seeds & place under a light source.
Now you are ready to plant your seeds in each plug (1-2 herb/lettuce seeds per plant site).
*Be sure to place your system under sunlight or an artificial light source to ensure your plants can photosynthesize!
- If it’s summer, consider placing your DWC hydroponic garden outside under the direct sunlight, or if one of your windows gets a ton of sun, place it there.
- If you have space under a coffee table, consider installing these lights on the bottom of the table and placing your DWC hydroponic garden under there.
- If none of your windows get enough sunlight, you can purchase an LED lamp to provide your plants with the lights it needs.