Types of Hydroponic Feedings

Wick

• The simplest of the hydroponic growing systems, the wick technique, uses a tray resting above a reservoir. The wick, which gives this mode its name, connects the nutrient solution-filled reservoir and tray. An aeration tube containing a piece of airstone, a porous mineral, filters and adds oxygen to the circulating nutrient solution. This is an easy and cheap system ideal for the beginner. It is a passive system not requiring pumps or timers and nearly any growing medium can be used. On the other hand, the wick system is limited in that large plants are unable to extract sufficient nutrients from the solution to thrive.

Water Culture

• Water culture is similar to the wick system. The bulk of the plant mass is supported by a Styrofoam mat floating on the nutrient solution. The roots are suspended in the solution, which is circulated and oxygenated by an air pump containing an inner airstone. This is a simple low-cost system for beginners that gives impressive results. Plants thrive with this form of cultivation, but not all are suited to this method. Additionally, large plants can't be sustained through water culture alone.

Drip

• The drip system is similar to the wick system, but with some refinements. Instead of relying on the passive action of a wick, a pump circulates the nutrient solution to the roots via individual supply lines. The continuous drip is more appropriate for use in large-scale greenhouse production than it is for the home hobbyist. The drip method requires timers and reliable pumps to ensure plants remain well-nourished and hydrated.

Flood and Drain

• Also called the ebb and flow system, this is an active recovery method. The plants are suspended on a floating platform above the reservoir. By means of a timer, the nutrient solution flows into the reservoir and bathes the roots for a set period of time. The solution is drained out and the roots remain suspended in air, giving them access to the oxygen they need. A large number of plants can be grown in a wide range of growing mediums. However, the pump needed to alternately flood and drain the reservoir requires a reliable power supply. Loss of power or pump can result in losing an entire crop.

Nutrient Film

• An active recovery mode, the nutrient film technique incorporates a number of features of flood and drain, drip, water and wick systems. The plants are suspended in grow tubes set at a slight angle to the bottom of the reservoir. This angle allows the pumped-in nutrient solution to bathe the roots, then drain off to be recycled continuously. The nutrient film technique requires no timer or growing medium that needs replacement, making it a favorite among beginning hydroponics enthusiasts. The pump requires a reliable power supply to operate. If the power fails or the pump malfunctions, an entire crop can be lost to dried-out roots.

Aeroponic

• Plants are suspended with their roots in the air within a specialized case. A misting system periodically bathes the roots in an aerosolized form of the nutrient solution pumped from a lower reservoir. Requiring a high level of technology and expertise, this is not a form of hydroponics for the beginner. Accurate continuous timing of the misting requires a failure-proof pump and power supply.