There are different methods that can be applied in hydroponics which is growing plants without the use of soil. The challenge lies on how to position the plants that will expose the roots to a constant supply of nutrient formula. There are a number of ways you can do this and some of these methods are more effective that the rest. Usually hydroponic systems fall into the classes of active or passive (active normally means a pump is used) and recovery or non-recovery (recovery means the solution is captured and re-circulated). Also, most systems will use some kind of grow tray to hold the plants, and a reservoir which holds the solution. Here are some common hydroponic systems you might be familiar with.

Ebb and Flow

This is an example of a system that employs the recovery method which anchors plants in mediums like rockwool. A pump motor floods the grow tray with water occasionally based on the time you set on the timer, it then shuts down and lets the nutrient solution drain through a maze of tubes attached to the tray that leads back to the reservoir. Also known (for obvious reasons) as flood-and-drain, this method is a popular choice for beginners.

The Drip System

This active method is comparable to ebb and flow, with the exception that rather than surging 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 preference you can turn the hydroponic systems into a recover or non-recovery system. The non-recovery variation is more low-maintenance because you do not have to keep track of the pH of the reservoir nearly as much.

The Wick System

This is a basic, passive non-recovery hydroponic method in which the nutrient formula is carried from the reservoir to the plant roots by means of a wick (like an oil lamp wick). There is no need for a pump and for water flow thus making this system simple and cost-efficient. Nonetheless, the yield may not be as impressive because regulating the water flow is a problem which means that the roots are getting too much or too little solution.

Nutrient Film Technique

Also called NFT for short, this is an active recovery system in which the plant roots are hanging in a continual flow (or film) of solution. A pipe is used as a grow tray and the plants are hanged on top while the roots are dangled and exposed beneath. The pump motor sends the formula into one end of the pipe, and it drains out the other end back again into the reservoir. This method may be effective but it can be complex and high-maintenance as well.

There are other types and variants of systems as well, but these are the most common hydroponic systems. Your skill level and finances will affect the choice that you make when it comes to hydroponic systems.