The wicking system is probably among the oldest form of hydroponics ever before the term hydroponics came into existence. It is a rudimentary system that does not need air or water pumps or electricity, thus the name, passive hydroponics.
In this system, plants are usually placed in absorbent medium like coco coir. Water and plant nutrients are transported towards the root using a wick – a rope or nylon. The wick runs through the plant root to the reservoir containing nutrient solution. It then carries the nutrient-filled water to the plant.
Among the advantages of the wick system is that it works well for beginners and small plants. However, it is not the best system for plants that need plenty water.
For some people, aeroponics is not considered a system of hydroponics but it is soilless gardening process and that should qualify it as one. It is the most technologically advanced form of hydroponics.
The plants are suspended in the air with the aid of foam inserts while the roots swing inside the reservoir. The root zones are then sprayed with the nutrient solution. Scientists believe this system with its technological advancement is best because it requires less land.
Aeroponics as a system of hydroponics is more favorable to plant growth because the roots have more access to oxygen, which helps them absorb more nutrients. But it is more expensive to set up.
Probably the easiest of all the hydroponics systems, this system is good for large plants and the ones that bear lots of fruit.
It uses a platform made of Styrofoam which holds the plants and floats on the nutrient. The growtray and the reservoir containing the nutrient are kept together, and then the roots are suspended within the nutrient solution, providing them with enough oxygen, nutrient and of course water.
Air pump with air stone is used to oxygenate the water and pump bubbles into the nutrients. Take care not to bubble the solution forcefully so as not to damage the tender roots with too much movement. In addition, the system must support the plant which is above the solution and inhibit light from getting to the solution to avoid the growth of algae.
When the plants are still tender, the nutrient solution should be changed once in every two weeks but as they begin to mature, make it once weekly. However, water should be added on daily basis to ensure that the level of the solution is kept constant.
The DWC system is easy and cheap to set up and maintain although it does not favor large plants and requires lots of water to maintain it.
The nutrient solution temporarily floods the growtray to a certain point, and then drains the solution away. This is dependent on size and type of plant. A timer connected to a submersedpump controls the power. After the set time, the timer goes off allowing the water to drain out.
There are automatic drainages that can be used too so that power is kept on to allow for more water and air movement over the roots.
Gravel, rockwool or grow rocks can be used as medium for ebb and flow system.
The major benefit of this system is that is allows for efficient use of energy and water but the roots can quickly dry out if anything goes wrong, like the timer.
Mostly used by commercial gardeners, because it can easily be managed at commercial scale, the drip system is of two types – recovery and non-recovery.
In recovery method, a timer can be used rather than controlling the water cycle but the level of nutrient strength and pH are observed. The non-recovery method is just the opposite, runs without interruption.
This system is constructed to slant slightly. It uses a submersible pump to pump the nutrient solution into the growtray but without the help of timer. The plants are placed in tubes with the roots dangling in nutrient solution but not completely submersed.
The medium is only air, that is a big advantage.