The growing medium in a hydroponics system refers to the material used to support the plants’ roots as they grow. This acts as a substitute for soil. The most common mediums include sponge, perlite, rice hulls, vermiculite, oasis cube, rockwool, and coco coir.
While the growing media is needed to support the plants as they grow, it is not really necessary for the plants to go grow properly.
In this article, we have provided a step-by-step guide to growing hydroponic plants without growing medium.
Hydroponics without Growing Medium: Step-by-Step Guide
Below, we have detailed how to grow your hydroponic plants without growing medium using two different hydroponic systems.
1. Ebb and Flow System
The ebb and flow hydroponics system or flood and drain system is a bit more complex in design but allows you to grow a wide variety of crops. The functionality of this hydroponics system is actually simple. It works by flooding the growing medium with a water-nutrient solution. After a while, it drains back the solution into the reservoir.
How to Set up A Ebb and Flow System With Growing Media
Materials
- Electronic timer
- Growing tray
- Hydroponic fertilizer and nutrients
- Two tubes (fill tube and drain tube)
- Submersible pump
- Bucket or basin for water reservoir
- Water
- Stand for growing tray
- Seedlings in net pots with growing medium
- Grow light
Instructions
Step 1: Set Up the Water Reservoir
Place the reservoir directly below the flood tray’s stand with the water and fertilizer. When adding water to the reservoir, you need to ensure it is clean and free of contamination. You can use the same water for about a week at a time, before renewing it. At the same time, you should renew the nutrients.
Step 2: Connect a Fill Tube and Drain Tube
You will have to connect the fill tube and the drain tube to the reservoir. Connect these tubes by connecting the reservoir to the tray. The fill tube will have to be attached to a submersible pump and controlled via a timer. This controls the flow of water into the flood tray. The drain tube works with gravity through which it pulls the water back into the reservoir after flooding. This allows the water to be reused.
Step 3: Connect a Submersible Pump and Timer
The submersible pump comes with an automatic timer that allows for control of the flooding action. You can customize the frequency of the watering based on your plant’s needs with the timer.
Step 4: Set Up the Flood Tray
The flood tray should be a large, shallow container that features a tall stand. The plants will have to sit on the flood tray. First, you need to place the seedlings in perforated pots. You won’t have to use a growing medium. When you choose the net pots, ensure that they are twice as deep as the flood tray.
Step 5: Set Up a Light Fixture
You can use a natural light fixture to save on costs. This should work perfectly. However, if you want better control of the lightning, you can set up a light fixture above the growing tray.
You can use incandescent light bulbs, LEDs, or fluorescent lights. If you go for incandescent light bulbs, set them 24 inches from the plants. LED and fluorescent lights do not produce as much heat so you should place them a lot closer. They should be 6 and 12 inches, respectively, from the plants.
2. Nutrient Film Technique
The nutrient film technique is another hydroponic technique that can be used without a growing medium. This technique makes use of a water-nutrient solution that constantly flows in a loop from a reservoir through a growing tray.
The plant roots are suspended in the growing tray and will absorb nutrients as the solution flows by. This system is much like the ebb and flow system but with the variation of being a continuously flowing system that never takes periodic breaks like the ebb and flow system.
The nutrient film system is most effective with fast-growing, shallow-rooted plants. You can grow lettuce, spinach, radishes, and herbs in this system.
Materials
- Bucket or basin for water reservoir
- Water
- Hydroponic fertilizer
- Two tubes (fill tube and drain tube)
- Air stone and pump
- Submersible pump
- Tube or PVC pipe to fit the seedlings
- Seedlings
- Net pots
- Grow light
Instructions
Step 1: Set Up the Water Reservoir and Aeration
Place the reservoir directly below the flood tray’s stand with the water and fertilizer. After that, add an aeration bubbler in the reservoir. This will oxygenate the water.
Step 2: Connect the Fill Tube, Drain Tube, and Pump
Using the fill tube and drain tube connects the reservoir to the tray. The fill tube will be attached to a submersible pump, which controls the flow of water up into the flood tray.
The drain tube allows gravity to pull the water back into the reservoir after flooding so that the water can be reused. Unlike the ebb and flow methods, you do not need a timer because it is continuously pumping the water.
Step 3: Set Up the Growing Tray
Instead of going for a flat tray, use a growing tray. With this method, you will need tubes or channels. The tubing should be set at an angle to ensure that the nutrient solution flows directly to the plant’s roots. There are several options to go for when it comes to tubing, you could choose a round tube or PVC pipe with holes drilled. The holes should be wide enough to fit the net pots.
Step 4: Set Up a Light Fixture
Plants need a light source for photosynthesis and to grow properly. You could choose to place the plants closer to a natural light source. If not, then you would have to provide a light source for the plants. For this, you will have to get a light fixture that can be set above the growing tray.
The distance from the growing trays depends on the type of lights. If you’re going for incandescent light bulbs, you can set them as far as 24 inches from the top of the plants. However, if you’re going for LED and fluorescent lights, you need to bring them a lot closer to 12 inches.