There are various methods that can be used in hydroponics which is gardening without the use of soil. The obstacle in each method is to suspend the plant in place while exposing the roots to a constant supply of water-nutrient solution. This can be carried out in several ways, quite a few more effective than others. Hydroponic systems have 4 categories the active which uses a pump, the passive, the recovery which requires recirculation of the solution, and the non-recovery. Also, nearly all systems will use some type of grow tray to hold the plants, and a tank which holds the solution. Here are some common hydroponic systems you might be familiar with. 

Ebb and Flow 

This is an case in point of a system that employs the recovery technique which anchors plants in mediums like rockwool. A pump motor floods the grow tray with water occasionally depending 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 tank. Also known (for obvious reasons) as flood-and-drain, this system is a popular choice for newbies. 

The Drip System 

This system is more or less the same with ebb and flow but instead of flooding the grow tray this method uses a pump that pushes the nutrient solution around the network of tubes that drips the solution directly on the plant roots. This hydroponic systems can be both recovery or non-recovery, depending on whether you strain the solution back into the reservoir. The non-recovery version 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 program is an case in point of a passive non-recovery hydroponic system in which the mixture gets to the roots through a wick. There’s no need for a pump and for water circulation thus making this system easy and cost-efficient. However, it also tends to be 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 mixture getting to the roots. 

Nutrient Film Technique 

Also called NFT for short, this is an active recovery system in which the plant roots are dangled 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 open below. The pump sends the solution into one end of the tube, and it drains out the other end back again into the reservoir. This method may be efficient but it can be complicated and high-maintenance at the same time. 

There are several variations of hydroponic systems but the types pointed out are the most common. Your skill level and budget will have an effect on the choice that you make when it comes to hydroponic systems.