Typically, experts branch hydroponic culture into at least five categories: passive, flood and drain, drip, deep water, and NFT. Some people prefer the terms ebb and flow rather than flood and drain and sprinkler to the term drip. Each system has advantages and disadvantages, and when choosing the best system, a grower needs to consider all the factors. Whichever one a person chooses, he or she should monitor the temperatures of the plant and its roots, the solution's pH levels and nutrient levels, and any pest or disease infestation. Choosing the best hydroponic culture is important because the systems are expensive to establish and maintain.
Hydroponic culture is a soil-less gardening technique that supplies the plant's roots with a pre-mixed solution of nutrients. To choose the best hydroponic culture, a person needs to consider several factors, such as the type of plants to be grown. Many orchid growers use hydroponics because it imitates orchids' native environment. Choosing a hydroponic system also depends on a person's expertise because some are tricky to master.
The easiest system for beginners is the passive technique. Some people refer to it as a self-watering pot because no mechanical system administers the solution to the plant's roots. Growers raise the plants in a nutrient-drenched medium, such as sand or aggregate. Frequently, the plants become root-bound and oxygen-starved; therefore this technique yields the lowest production rate.
Another popular system is the flood and drain technique. In this system, the grower raises the plants in a medium on a special table that he or she floods with solution. The plants absorb as many nutrients as possible, and then the excess drains into a reservoir or waste container. Several factors, such as expense and the grower's expertise, determine if this is the best hydroponic culture for the grower. Some mediums, such as rock wool or mineral wool, are expensive.
The deep-water technique is a hydroponic culture technique that beginners may consider. In this technique, a tray filled with a growing medium sits on top of a solution-filled reservoir. A pump forces air through air stones to oxygenate the solution, but the deep-water technique does not use a pump to recirculate the solution. One of the drawbacks of this hydroponic culture technique is that it requires a lot of space.
The drip or sprinkler system also requires a circulation pump. The solution constantly flows over the roots, and, in some systems, the sprinklers mist the leaves to deliver more nutrients to the plants. Some of the disadvantages of this system include clogged nozzles, leaky hoses, and salt buildup in the irrigation system. System failure quickly dehydrates the plants because the roots are openly exposed. Generally, experts do not recommend this system to beginners, but the yield is higher.
The NFT system is the most productive but the most complex. The grower does not use a medium to anchor the plants or to hold the solution in place. He or she places the plants in a collar in a sloped, open gutter or a closed pipe, letting the roots flow freely in the gutter or pipe. Solution continuously flows over the roots. A grower must be diligent in keeping the pump running, or the plant roots will dehydrate and die.