Types of Hydroponics
The market is full of many different types of hydroponics systems, and it can be hard to pick the right one. The hydroponics system you end up buying will have a big influence on how much time and money you need to maintain your garden, which hydroponics nutrients you buy, and what plants you are able to grow. There are two main kinds of system: active and passive. Passive types deliver nutrients via the growing medium, but active systems use a pump. An active system will cost more and take more to maintain, but may get better results.
Below are examples and explanations of the most popular hydroponics types being used today:.
Aeroponics - This method is probably the most high-tech type of hydroponics gardening. Aeroponics Systems use little to no growing medium. The roots hang in the air and are misted with nutrient solution. The misting is usually done every few minutes. Because the roots are exposed to the air, the roots will dry out rapidly if the misting cycles are interrupted. However, managing the hydroponic garden is even trickier, since disease and pests have it much easier in this setting. Plants are continuously kept wet, either immersed in water ('true' hydroponics) or continually sprayed (aeroponics) or reside in a permanently wet medium such as perlite or sand. Fortunately, as with soil-based gardens, there is a large array of available methods to manage the problem.
A timer controls the nutrient pump much like other types of hydroponic systems, except the aeroponics system needs a short cycle timer that runs the pump for a few seconds every couple of minutes. Other types of Aeroponics systems run constantly, requiring no timer. These systems are easily contaminated by rot-inducing anaerobic bacteria, and should only be used by experienced gardeners and researchers.
Deep Water Culture - This is the simplest of all active hydroponics systems. Plants are in a basket of grow rocks, suspended over a container of aerated nutrient solution. An air pump supplies air to the air stone that bubbles the nutrient solution and supplies oxygen to the roots of the plants.
Water culture is the system of choice for growing leaf lettuce, which are fast growing water loving plants, making them an ideal choice for this type of hydroponics system. Very few plants other than lettuce will do well in this type of system, although it can work well for the vegetative stage of flowering plants. This type of hydroponics system is great for the classroom and is popular with teachers. A very inexpensive system can be made out of an old aquarium or other water tight container. The biggest drawback of this kind of system is that it doesn't work well with large plants or with long-term plants.
Ebb and Flow - Ebb and Flow works by temporarily flooding the grow tray with nutrient solution and then draining the solution back into the reservoir. This action is normally done with a submerged pump that is connected to a timer. When the timer turns the pump on nutrient solution is pumped into the grow tray. When the timer shuts the pump off the nutrient solution flows back into the reservoir. Depending on plant requirements, the tray can be flooded once, or several times, each day.
The main disadvantage of this type of system is that with some loose types of growing medium (Growrocks, Perlite, etc.), there is a vulnerability to power outages as well as pump and timer failures. The roots can dry out quickly when the watering cycles are interrupted. This problem can be relieved somewhat by using growing media that retains more water (Rockwool, coconut fiber or a good soilless mix). This is the system we often recommend for first-time hydroponics gardeners. It is simple, reliable, and easy to set up.
N.F.T. System - N.F.T. systems have a constant flow of nutrient solution so no timer is required for the submersible pump. The nutrient solution is pumped into the growing tray (usually a tube) and flows over the roots of the plants, and then drains back into the reservoir.
Normally the plant is supported in a small plastic basket full of grow rocks, with the roots dangling into the nutrient solution. N.F.T. systems are very susceptible to power outages and pump failures. The roots dry out very rapidly when the flow of nutrient solution is interrupted.
There is usually no growing medium used other than air, which saves the expense of replacing the growing medium after every crop. Normally the plant is supported in a small plastic basket with the roots dangling into the nutrient solution.