Hydroponic Systems and Grow Media Basics

Hydroponic gardening really is easy, once you learn the basics and have spent a little time fine-tuning your system. Fact is, much of the work is in learning all the basic info, setting up, and adjusting your first system. We are here to help.

Hydroponic gardening boils down to simply this: The food is in the water. How to get food/water, also called nutrient solution, to your plants requires a look at the different hydroponic gardening systems. As you look over each type of system, you will see how each one addresses the three major concerns:

  • How to get the nutrient solution to the plants
  • How to keep the plants from drowning
  • How to make sure there are no problems
 
Hydroponic Growing Systems
There are as many ways to deliver the nutrient solution to the plants as you can possibly think of. These are the main types of hydroponic systems organized by skill level (low to high):
  1. The Drip System
  2. Deep Water Culture (DWC)
  3. Ebb & Flow
  4. Nutrient Film Technique (NFT)
  5. Aeroponics
  6. Aquaponics
  7. The Wick System
 
The Drip System
  • Skill level: low/medium
  • Setup: 2 hours (first crop); 20 minutes subsequent
  • Maintenance: 15-60 minutes/week
  • Space: small/large
Drip systems are probably the most widely used type of hydroponic system in the world.
Operation is simple, a timer controls a submersed pump. The timer turns the pump on and nutrient solution is dripped onto the base of each plant by a small drip line. With the drip system, the plants are in their own tray, separate from the nutrient reservoir. A pump pushes nutrient solution through many small tubes, which feed each plant from the top. Different emitters can be placed on the end of each tube to make the drip slower or faster.

A faster draining medium (like clay pellets) will need faster dripping emitters (or more of them per plant). Slower draining media (like rockwool) would require slower dripping emitters.

The standard media for drip systems are expanded clay pellets and rockwool, although lava chips and perlite are occasionally used.

View our selection of Drip systems.

 
Deep Water Culture (DWC)
  • Skill level: low
  • Setup: 15 minutes
  • Maintenance: 15 minutes/week
  • Space: small
The deep water culture method, also known as the reservoir method, is one of the easiest of all the true hydroponic growing systems. A reservoir holds the nutrient solution. Several net pots sit down in the nutrient solution. An air pump constantly bubbles in the nutrient solution, oxygenating and keeping the roots from drowning.

It is important to keep light from getting to the nutrient solution. Wherever there is light and nutrients, algae will grow. Algae eat the nutrients you are trying to feed to your plants, and when pieces of algae die they attract fungus gnats. Fungus gnats lead to many other problems.

Since there are no drip or spray emitters to clog, DWC is a good choice for organic hydroponic growing systems. This system is well suited for volcanic lava chips media, vermiculite and expanded clay pellets.

View our selection of Deep Water Culture systems.

 
Ebb & Flow
  • Skill level: medium
  • Setup: 2 hours (first crop); 20 minutes subsequent
  • Maintenance: 15-60 minutes/week
  • Space: small/large
In the ebb & flow method (also known as the flood and drain method), the plants sit in their own container separate from the nutrient reservoir. On a set schedule, a pump transfers the nutrient solution from the reservoir to the grow tray where the plants are located, soaking the plant roots and the grow medium. The pumps then turn off, and the solution drains back into the reservoir.

Your choice of grow media determines how often and how long you should flood the grow tray. Fast draining expanded clay pellets may be flooded for a half hour 4 times a day, while the slower draining rockwool can be watered less. This system is also well suited for growing in straight perlite or lava chips.

View our selection of Ebb & Flow systems.

 
Nutrient Film Technique (NFT)
  • Skill level: high
  • Setup: 2 hours (first crop); 30 minutes subsequent
  • Maintenance: 15 minutes/week
  • Space: medium/large
In the nutrient film technique, plants are placed in a tray, tube or “gutter” separate from the nutrient reservoir. One end of the tray is lower than the other, to encourage the flow of water.

A pump delivers a steady flow of water at one end, creating a constant stream of nutrient solution in the bottom of the tray. In order to make sure the water flowing through the bottom of the tray is nice and even, a layer of absorbent material (called capillary mat) is placed in the bottom.

NFT is a good choice for organic hydroponic growing. There are no drip or spray emitters to clog. One thing to consider, however, is you must start with plants that have a root system large enough to hang down into the flowing nutrient solution. Your other option would be to top feed the plants with a drip system until their roots are large enough (this requires a lot of time and patience).

It doesn't matter what type of media you start your plants in. Once positioned in the NFT system, the roots will be growing right in the water. This system, when properly set-up and maintained, works very nicely.


 
The Aeroponic System
  • Skill level: high
  • Setup: 2 hours (first crop); 30 minutes subsequent
  • Maintenance: 15 minutes/week
  • Space: small/large
In aeroponic systems, a large container contains several gallons of nutrient solution in the bottom. A pump pushes nutrient solution through spray heads that constantly soak every inch inside the container with a fine mist of nutrient solution. The pump must be a high-pressure pump, and the spray emitters are made specially to deliver a very fine, highly oxygenated spray.

There is no growing medium in aeroponic systems. The roots hang down into the container and grow mostly in air, except for the few that grow long enough to make it into the nutrient solution on the bottom.

It is often very hard to assemble individual parts into a well-working system, and the individual parts can be expensive as well. Also, the fine-spray emitters will instantly clog if you try to use anything except high quality hydroponic fertilizers (no organics).

Of all the hydroponics growing systems, this is the most difficult to master and the most temperamental. pH changes and nutrient imbalances occur more quickly because of the increased absorption rates and high levels of oxygenation. Furthermore, with no grow media to protect the roots, the plants react negatively to these changes much more quickly. If you can keep up with the maintenance of an aeroponic system, aeroponics generally provides for faster growth rates.

View our selection of Aeroponic systems.

 
The Aquaponic System
  • Skill level: medium
  • Setup: 2 hours (first crop); 30 minutes subsequent
  • Maintenance: 15 minutes/week
  • Space: small/large
Aquaponics is a form of hydroponics involving the simultaneous cultivation of plants and aquatic animals such as fish. In this system, animal effluent accumulates in the fish tank. This water is then fed into the hydroponic system where the by-products are filtered out by the plants as nutrients. The clean water is then recirculated back to the fish tank.

View our selection of Aquaponic systems.

 
The Wick System
  • Skill level: low
  • Setup: 15 minutes
  • Maintenance: 15 minutes/week
  • Space: small
In wick hydroponic systems, the plants are in their own container, separate from the nutrient reservoir. Pieces of absorbent material (usually nylon rope) are buried partially in each plant container. The other end of the rope is allowed to dangle in the nutrient solution. The absorbent material pulls the nutrient solution from the reservoir up into the growing medium.

The system is a good choice for organic hydroponics, but there are a couple of things to consider:

Sometimes it is difficult to get the right moisture level in a wick system. You will have to experiment a little with more absorbent growing mediums (vermiculite/coconut coir). Also, over time, the wicks suck up less and less solution - especially when using organic nutrients.

A 50/50 mix of perlite/vermiculite is usually a good medium for this system. Perlite and coconut coir also work well. Most often, the other hydroponic systems are just as easy to use, and produce better results.
 
The Media
Except in the case of aeroponics, you have to grow your roots into something besides air. The best hydroponic media is:
  • nutrient free
  • neutral pH
  • able to retain water
  • able to retain air
  • able to drain quickly
Just as there are many hydroponic growing systems, there are many different types of grow media. Some types of media are better suited for certain grow systems, so you need to do a little research. The best media that meets the above requirements and that people most commonly use are:

Ready to get your hydroponic garden started? Take the 1 hour Hydroponics 101 class or learn more in the GYOstuff Learning Center.
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