With so many different types of hydroponics systems available, indoor growing can become somewhat confusing. But when you get down to the basics, you’ll find there are only six different types of hydroponic systems.
These basic systems come in different configurations, sizes and even materials. You might also see several basic systems combined into one system. All this can make the various basic systems look different.
This is the simplest hydroponic system. It has no moving parts and works the same way as an oil lamp. In other words, the nutrient solutions are wicked up to the plant as it is being used.
Your plants are placed in a growing medium which is kept moist by wicks. These wicks are made from a strip of highly absorbent material such as felt or cotton. The wick runs through the growing medium and out the bottom into a container of nutrient solutions. These wicks constantly replenish the moisture in the growing medium.
Water Culture System
You may hear it called ‘bubbleponics’ but the real name is, ‘Water Culture. ‘
With this system, the roots of your plants are suspended directly into the nutrient solutions. It is usually constructed of Styrofoam which floats like a raft on top of the solution. Then you cut holes in the Styrofoam for the plants.
The most important part of the system is an air pump attached to an air stone. This generates a continuous flow of tiny air bubbles so the roots can breathe. Otherwise, the totally submerged roots will tend to suffocate.
Ebb & Flow (Flood & Drain)
As we look at each of the basic systems, you’ll notice that each becomes a little more difficult than the previous system. For example, this system requires a submersible water pump and a timer set to run in cycles.
There are many ways to build this system but the basic principal is always the same. A reservoir filled with your nutrient solution is placed below the plants. This creates a siphoning action which drains the solution back into the reservoir when the pump shuts off. The timer cycles the pump on and off to flood the system and keep the roots moist.
In the grow tray an overflow tube is placed which usually rests about two inches below the top of the growing medium. This allows the water level to rise high enough to saturate the root system but not so high as to cause root rot problems. The overflow tube also prevents the solution from overflowing out of the grow tray. The excess solution flows directly back into the reservoir for reuse.
Nutrient Film Technique (NFT System)
First of all you don’t need a timer because the solution flows 24/7. But like the Ebb & Flow, there’s a reservoir that sits below the level of the plants.
The solution flows along the bottom of the containers that hold the plant roots. The bottom roots are then able to reach into the solution and wick up moisture to the upper roots. This enables the upper roots to still get the air and oxygen they need to grow. The solution then flows back into the reservoir and is recycled past the plants again and again.
There are many ways to build a NFT System. Generally they are laid out as a series of tubes in rows that hold the plants. These tubes are tilted downward to facilitate the flow of nutrients.
A pump delivers the solution to the top of the tube and gravity takes care of the rest. Because the system is easily expanded, you can have hundreds of rows operating within just one set-up.
If you’re familiar with drip irrigation system used in outdoor gardening, you are also familiar with a hydroponic drip system. The difference is that instead of plain water, you use a nutrient solutions .
There are two ways to run a drip system. Both are set up essentially the same way. The nutrient solution is pumped through the lines to the plants where it drips down through the growing medium, and when it reaches the bottom, one of two things happen.
Either the nutrient solution is captured and sent back to the reservoir through return lines. This is most popular and economical system. However, in using this system, keep a close check on your solution.
Each time the solution passes through the medium, some of the nutrients are used up and the pH will gradually change. Frequent readings will tell you when to add more nutrients or completely drain the reservoir and refill it with new.
A non-recovery system avoids this problem by allowing the nutrient to either drip on the ground or be directed to a waste drain.
This system is very much like the Ebb & Flow system. The big difference is that the roots are completely suspended in the air. To keep them moist with solution, they are frequently sprayed with misters.
The nutrient solution then drips down off the roots and is collected in a reservoir to be sprayed again. It's important to use a timer with this system which can be set to cycle on and off many times a day. Otherwise, the roots will tend to dry out.
It’s also important to frequently measure the pH and PPM of your solution. Over a period of time the pH will change and nutrients within the system will be used up.