October 2013 Newsletter (vol.22)   >>   Why Hydroponics…



Hydroponic Lettuce

Hydroponics is a method of growing plants without using soil. This method focuses on getting plants the exact nutrients they need, exactly when they need them. Hydroponic systems achieve this by delivering a specific nutrient rich solution directly to the plant roots, eliminating the buffering of soil and the plants’ need to search for these nutrients. Because of this, plants can focus all of their energy on growth. The result: plants that take less time to grow and are generally larger and more productive than soil-grown crops. While there are countless ways to grow plants hydroponically, the following are some of the more common systems.

The Wick System

The wick system is a very simple, passive hydroponic system. The nutrient solution is drawn from a reservoir via a wick. Nylon is a good choice for wick material due to the fact that it is not very susceptible to algae and mold. While it is not the best unit for larger plants, it can be used with any type of hydroponic media.


Water Culture


Water culture is the simplest active hydroponic system. Plants float on rafts, usually made of Styrofoam, and the roots are left to hang in the nutrient solution. An air stone and a pump are required to deliver oxygen to the solution. This is an inexpensive model and is a great choice for educational settings. It is the ideal choice for leaf lettuces but does not do well for other plants or long term growth.


Ebb and Flow


Ebb and flow systems use a timer and a pump submerged in a nutrient solution reservoir to flood a grow tray. Once the pump has run a significant amount of time, it shuts off allowing the tray to drain. The entire tray can be filled with a medium or the plants can be placed in individual baskets for ease of movement. Timing of flooding depends on the plants and the growing environment, but should be easy to establish. The biggest drawback to this system is the threat of the pump losing power and the tray not being flooded causing a loss of plants.


Drip System


One of the most widely used hydroponic methods is the drip system. Plants grow in individual pots in media with a dripper placed at the base of the plant. A pump and time deliver nutrient solution from a source to the drippers for a set amount of time. These systems can be recovery, where water would be collected back into a reservoir, or non-recovery in which the water would come directly from a source and then out to a drain. The non-recovery requires less attention because you do not have to monitor and change a reservoir. Dutch bucket systems are a form of drip hydroponics.


Nutrient FIlm Technique


Nutrient film technique (NFT) is probably the system that most people envision when they think of hydroponics. Plants are placed in baskets in a trough system. The nutrient system is constantly cycled through the troughs and over the roots of the plants. While root cubes of different material can be used, no media is necessary. This system is fantastic for lettuces and herbs such as basil. The only concern with this setup is that the pump will lose power and water flow will be cut off from the plants.


Aeroponic System


One of the most high-tech versions of growing hydroponically is using an aeroponic system. As with NFT, no media is necessary as roots are suspended in the air where misters deliver the nutrient solution to the root zone. This system pulls the solution from a reservoir by using a submerged pump and requires a short cycle timer as the misting will have to occur fairly often.

One thing to remember in all of these systems, and in any hydroponic setup, is that paying close attention to the pH and EC of your solution is paramount. This can be done with a meter that checks for both of these such as our hydroponics combo tester.

It is also important to change your solution often, about once a week, to ensure that the correct amount of nutrients is being delivered and to keep the system clean. The reservoir and other parts can be cleaned with products such as Zerotol or Terraclean. A great way to ensure that you are starting with pure water is by using a reverse osmosis filter. All of these systems and more will be featured in our upcoming catalog. Ask your sales rep for more information.