Types of Hydroponic Systems

There are 7 basic types of hydroponic systems. Here’s how each of them works.

1. Wick System

This system, named for its functional resemblance to a candle wick, is the simplest setup. Nutrients are pumped from a water reservoir, via a string, up to the growing medium that holds the plants. This approach is a popular choice for home gardeners who want to give hydroponics a try. But it isn’t great for larger plants because a string isn’t able to provide enough water for them. And an incorrect setup or material use can be fatal to the plants.

2. Deep Water Culture System

Also called the Kratky Method, after its creator, the University of Hawai’i horticulturist B. A. Kratky (who, and I am not making this up, received a degree in “Weed Science” from Purdue University in 1971), this system works by placing plants in pots on top of a floating holder so that the roots are in the growing medium. It recirculates water, reducing waste, and is inexpensive and very low maintenance. However, this method isn’t a good fit for large plants either, or plants that have long growing periods because they have to be lightweight enough to be well supported by the floating raft.

3. Nutrient Film Technique (NFT) System

This system is used in many vertical farms, which are essentially plant skyscrapers. Some can house thousands of square feet of hydroponic growing systems. NFT is also the most common type to use in home, lab, and commercial settings. It works by allowing a continuous nutrient flow to the plant and back to the reservoir using a slightly downward-facing tube. This design has two advantages: it doesn’t require a timer because the pump runs 24/7, which is one less thing to set up (but could be problematic in a power outage). And it does away with the need for a growing medium. But it’s a little more high maintenance as growers have to watch that the plant roots don’t grow in a way that clogs the system. And they have to periodically make sure the pump is working properly, so the plants are getting adequate nutrients.

4. Ebb and Flow System

This method uses a pump on a timer to regulate nutrients going from the reservoir to the growing tray. The nutrients drain back into the reservoir after they have thoroughly encompassed the plant roots. This system can be customized to fit the grower’s needs, and efficiently uses water and energy, but requires a significant amount of growing medium.

5. Drip System

This system uses a timer that controls when the nutrient solution is transferred through a group of drip lines to provide tiny drops of water for the plants. It’s relatively inexpensive and gives more control over the schedule. But it’s probably overkill for a small garden at home and can waste a lot of water.

6. Aeroponics

Aeroponics seems to be one of the most complex hydroponics options. Plants are suspended in the air, requiring no growing medium. And a timer controls a spray system to frequently deliver nutrients to the roots. As such, the roots are exposed to more oxygen using this system.

7. Aquaponics

In aquaponics, fish — and sometimes other aquatic animals like snails, prawns, and crayfish — and crops are combined into one symbiotic system. Waste products that can be harmful to fish in high concentrations are filtered out of the system by the plants, which use them for their own nutrition. While fish farming is often environmentally disastrous, not all fish farms are the same. Aquaponic farms are unique because they combine fish farming with hydroponics, and the two work together to create what at least has the potential to be a more sustainable system in which each element can benefit the whole.