Hydroponics – the gardening of crops without soil – can be achieved by a wide selection of methods. The challenge lies on how to position the plants that will expose the roots to a continuous supply of nutrient formula. There are several ways you can do this and some of these methods are more efficient that the rest. Usually hydroponic systems fall into the categories of active or passive (active generally means a pump is used) and recovery or non-recovery (recovery means the solution is captured and re-circulated). Also, nearly all systems will use some type of grow tray to hold the plants, and a tank which holds the solution. With these items in mind, here are a few of the most common hydroponic systems.
Ebb and Flow
In this active recovery method, crops in the grow tray are usually anchored by some sort of medium (ideally one that retains water, like rockwool). A water pump on a timer regularly floods the grow tray with nutrient formula from the reservoir, then turns off and allows the solution to drain back through tubes into the reservoir to be reused. This technique is otherwise known as the flood-drain system which is very popular among beginners.
The Drip System
This active method is similar to ebb and flow, except that rather than flooding the grow tray, the pump sends the solution through a network of tubes that drip the solution straight onto the plant roots. Based on your choice you can turn the hydroponic systems into a recover or non-recovery system. The non-recovery version is more low-maintenance because you don’t have to monitor the pH of the reservoir nearly as much.
The Wick System
This is a basic, passive non-recovery hydroponic system in which the nutrient solution is carried from the reservoir to the crop roots by means of a wick (like an oil lamp wick). Absolutely no pump is needed, and the water is not re-circulated, making it one of the simplest and least expensive systems. However, it also tends to be much less productive because it is tougher to regulate the water flow, which means (depending on the type and quantity of plants) there can be either too much or too little solution getting to the roots.
Nutrient Film Technique
Also called NFT for short, this is an active recovery method in which the plant roots are hanging in a regular flow (or film) of solution. The “grow tray” is generally a tube, where the plants are suspended on top and the roots are exposed below. With the pump motor the solution passes through one pipe and drains on the other end and into the reservoir. While effective, this approach is also more complex and higher-maintenance.
There are a number of variations of hydroponic systems but the types pointed out are the most popular. Your skill level and finances will have an effect on the selection that you make when it comes to hydroponic systems.
