Various methods of hydroponics each offer their own advantages and disadvantages. The type of system you decide to use will depend on your budget, the scale of your crop and the type of plants you intend to grow.
Six Basic Methods of Hydroponics
All hydroponics systems work on the same principle: plants grow in a sterile, soil-less medium that allows delivery of nutrients to the roots directly from a nutrient-enriched water solution. These systems differ primarily in structure. Each of the following six systems utilizes a unique method to deliver nutrients to the growing plants.
Just as the name implies, this system uses one or several wicks to draw nutrient solution from a reservoir into a sterile medium such as perlite, vermiculite or rockwool. A wick system is cheap and simple to set up and doesn't require any pumps or elaborate drainage systems.
Plants grow directly in the medium and take up the nutrients as needed. These systems are ideal for small set-ups such as an indoor kitchen garden or collection of house plants. It is not, however, the most efficient delivery system and may not be able to adequately keep up with the needs of large or rapidly growing plants.
A drip system employs an intricate system of hoses and drip lines to take nutrient solution to each individual plant. Each plant is usually rooted in a fairly solid medium, such as rockwool cubes to prevent clogging of lines. This type of system works well for larger plants, such as tomatoes, that need to grow for an extended period of time before harvest.The main drawback to drip systems are cost and maintenance. The many drip lines, emitters, pumps and paraphernalia can be prohibitively expensive for a small hobby garden, and clogged or leaky lines are common problems. Cleaning this intricate system can be difficult and time-consuming, possibly making your fun new hobby more trouble than it's worth.
Ebb and Flow
An ebb and flow system uses a timed pump to regularly flood and drain a growing table, on which plants are rooted in a sterile medium. The regular flooding keeps the roots moist and well-fed, while the drain cycle ensures they are able to get enough oxygen. This system is not overly costly, is easy to maintain and is not prone to many of the problems associated with other systems.While this system is easy and practical for a greenhouse setting, it doesn't lend itself well to a small, kitchen-counter or sunroom garden. Tables are usually built to be sturdy and practical, but not necessarily attractive. Unlike the drip and wick systems, it can be hard to make an ebb and flow system pretty.
Nutrient Film Technique
This system is also better suited to a greenhouse or larger operation than for an in-home project. The Nutrient Film Technique (NFT) has plants suspended in plastic baskets and sometimes small rockwool cubes over long tubes or trays. Nutrient solution flows through the tubes onto the plants' roots and then drains back into the reservoir.This system offers a number of advantages. With no tiny drip lines or timers, there are fewer components that could potentially cause problems. Individual plants can be removed and replaced without disturbing the rest of the system. One potential drawback of the NFT system is that any system failure or power interruption leaves the roots vulnerable to rapid drying.
Water culture is the system most often used commercially to produce small, water-loving, quick-growing plants like lettuce or spinach. It is generally little more than a tray, made of Styrofoam or similar material, floating on the reservoir. This system can be as large or as small as you want and is easily adapted to any number of settings. However, it is not the best choice for large or long-lived plants, or those better adapted to drier conditions.
Similar to the NFT, aeroponic systems have bare plant roots suspended in little or no growing medium. Rather than flowing through the system, nutrient solution is continually misted on the suspended roots, allowing for maximum uptake of water, nutrients and oxygen. This is perhaps the most efficient delivery system, but also the most expensive. Like the drip system, there are numerous small parts that need to be purchased, cleaned and maintained. However, if you can afford the initial outlay, this system will probably give you the best results for your investment.
If you're still not sure which of the many methods of hydroponics are best suited to your plans, start with a small, basic system and become comfortable with hydroponic methods before you try to expand or invest too much money in the latest, greatest system. Hydroponic gardening requires experience moderating nutrient levels, water pH, light levels, humidity and even indoor pest control. Getting to know your plants and materials before you take on a large project will minimize stress, ease the learning curve and ensure a successful first crop.