Wick, Ebb or Drip? Hydroponic systems types demystified!
As you probably know hydroponics is a method of growing plants using mineral nutrient solutions in water with no soil. Plants can be grown with roots in the mineral nutrient solution only, or in an inert medium such as gravel.
The medium that holds the plant and its roots, can be any type of sterile material. These mediums are generally inexpensive and easy to find. Gravel, pebbles, and peat are examples of inexpensive mediums to grow your plants. These materials are usually readily available at local nurseries, and some hardware stores. At Niwa we use rockwool but you can really use whatever you want.
There is a very important characteristic of hydroponics that needs to be understood. Hydroponic growing depends on the air surrounding the roots, not just the constant injections of nutrients and water. It is easy to forget, plants breathe in carbon dioxide, but the plants’ roots breath in oxygen. So, hydroponic growing is as much about boosting the root systems with oxygen as it is supplying nutrients and water. This is one of the advantages of hydroponics because the roots are not buried in soil so air can easily saturate the roots.
But although hydroponic systems follow the same rules there is a variety of ways to deliver the water and nutrients to the plants. Below we will outline a variety of hydroponic systems and explain the main differences.
There are six basic hydroponic systems. They are Wick, Water Culture, Ebb and Flow, Drip, N.E.T and Aeroponic. All hydroponic methods are a combination or variation of these six methods.
The Wick System
The Wick system is the simplest hydroponic system, mainly because there are no moving parts. The nutrient solution is drawn into the growing medium from the reservoir with a wick. Vermiculite and Coconut Fiber are among the most popular growing mediums for this method. The major drawback of this system is that large plants that use large amounts of water, may use up the nutrient solution faster than the wick can supply.
The water culture system
The water culture system is the simplest of the active hydroponic systems. The platform for holding the plants is usually made of Styrofoam and floats directly on the nutrient solution. An air pump is used to supply air to the air stone that bubbles the nutrient solution and supplies oxygen to the roots of the plants. This system is excellent for growing leaf lettuce, which is a fast growing plant. There are very few plants other than lettuce that will grow using this system.
The Ebb and Flow system
The Ebb and Flow system temporarily floods the grow tray with nutrient solution and then drains the solution back into the reservoir. This is usually accomplished using a submerged pump connected to a timer. The timer is set to come on several times a day depending on the type of plants, and temperature and humidity for the type of growing medium you are using. When the timer turns on the pump, nutrient solution is pumped into the grow tray. Then the timer is turned off and the nutrient solution flows back into the reservoir. This is a versatile system that can be used for a variety of growing mediums.
The Drip Systems
The drip systems are the most widely used hydroponic systems in use due to their simple setup. A timer is used to control a submersed pump. When the timer turns the pump on, nutrient solution is dripped onto the base of each plant using a drip line. In a recovery drip system the excess runoff solution is collected back in the reservoir to be reused. If the non-recovery system is used, the runoff is not collected.
In an NFT system, there is a constant flow of the nutrient solution so no timer is required for the submersible pump. The nutrient solution is constantly flowing without the need for a timer. The nutrient solution is pumped into the grow tray and flows over the roots and drains back into the reservoir. In this method, there is usually no growing medium other than air. This saves the expense of replacing growing medium after every crop. The plant is supported in a small plastic basket with the roots dangling into the nutrient solution. Be aware these systems are very susceptible to power outages and pump failures. The roots dry out rapidly when the flow of nutrient solution is disrupted.
A variation of hydroponic growing is Aeroponic. The growing method is mainly air. The roots hang in the air and they are misted every few minutes. Like the other systems, the roots will dry out quickly if the misting cycles are disrupted. This method also is controlled by a short cycle timer so the pump cycles the nutrients every few minutes.
In conclusion, remember, as long as there is enough oxygen provided to the roots, the root systems will stay healthy since they do not need to search very far for nutrition as long as the system used complements the plants you are raising. The most important thing to remember is plants need more air than water. The most common error made in growing hydroponics is the lack of oxygen to the roots. Roots should always be bright white. Any sign of browning roots is an indication your roots are being deprived of air.
Which systems have you used in the past? Which have your found the most easy to use?
We would love to hear about your experiences.