Friday, August 6, 2010

Hydroponics & Hydroculture, What's The Difference?

Hydroculture is a hydroponic wick system. huh?

I know hydroponics can be confusing to the traditional gardener at first.  It was for me.  There are so many varieties and seems so high-tech with the air pumps and air stones, but it's really quite simple.

Hydroponics it is the art of gardening without soil.

There are six basic kinds of hydroponic systems with hundreds of possible variations. For more information on the different methods of hydroponic gardening check out this website.  It is by far one of the best explanations of all the hydroponic systems there are ("Basic Hydroponic Systems and How they Work").

Hydroculture is also called a 'passive-hydroponic' system or a wick-system and is just a form of hydroponics that is static.  In other words, there are no moving parts, the water is stagnant.  Now if bells are ringing and you're saying, "stagnant water!  Roots can't be in stagnant water", you're right, and in a healthy hydro-culture the roots should not be immersed in water for an extended period of time.  Instead, capillary action of the soil less media is used to bring nutrients to the plant.  Hydroculture is very similar to a self-watering container in that sense, except it uses no soil. Which comes with some added benefits.

There are 3 things needed to grow a plant in hydroculture:

  1. Inert Growing Medium
    In hydroculture, plants are grown in a media that allows for the distribution of water and nutrients through capillary action (a wick). What is used as a wick? A wick can be as simple as a paper towel, or aquarium gravel to more complex forms such as clay pebbles, perlite, gravel, vermiculite or rock wool.  (While you can grow plants with paper towels or aquarium gravel, the latter five medias are designed specifically for hydroponics, and these are the best solutions if you are serious about growing plants hydroponically .)
  2. Water Solution
    This is the 'food and water' for the plants. Hydroculture nutrients differ from some houseplant foods in that they need to be soluble in water.  Nutrients are available in many different NPK (N=Nitrogen, P=Phosphorus, K=Potassium) formulations that are expressed as percentages. By selecting different NPK formulations the growth, flowering or crop of the plant can be controlled to a certain degree. Most of our liquid fertilizers, however, can not be classified as organic, even though hydroculture gardening is sometimes more organic than soil gardening.  More on organic gardening and hydroculture in a later article.
  3. Containers 

    There are 3 methods of potting in hydroculture that I use:

    1. A single pot: A single pot filled with inert growing medium.  I use glass, but you can also used recycled containers. If the container is see through you can visible see when the plant needs water.  And it's kinda cool to see the root growth.  The downside to a single pot is that it needs to be rinsed once a month and is more vulnerable to algae.  UPDATE:  It also heats up the water in the reservoir really fast.  With the recent heatwave, I've really been cooking my plants and I've had to repot most of my outside plants to the 'Pot And Saucer' or Pot in Pot methods.
    2. Pot And Saucer: This method uses a standard plant pot, with bottom drainage holes, which is placed into a large plant pot saucer. A saucer which is larger than the usual size for the pot is chosen so that it can work as a reservoir.  The larger the reservoir, the longer it can be left alone without watering.  The nutrient solution is stored in the saucer. It is possible to get transparent saucers and these make the checking of the nutrient solution level even easier. If several plants are grown in close proximity then, instead of using a seperate saucer for each plant, a large watertight tray can be used to house several pots. A tray without drainage holes is used such as a garden tray or a gravel tray.
    3. Pot in Pot Method: This is very similar to the pot and saucer method above except that the plant pot is placed into an watertight pot container instead of a saucer. A plastic pot container which is slightly larger internally than the plant pot, by approximately 1cm all round, is chosen. This allows space which will act as the reservoir. With this method it is more difficult to see the nutrient level, so the pot either needs taking out or a level indicator needs to be used in order to check the nutrient level. Alternatively a transparent plastic pot container can be used but this possibly defeats one of the reason for using a pot container i.e. it does not disguise the plant pot. With this method I try to get a nutrient level height of approximately 1/4 of the inner pot. The level is measured when the system is assembled, i.e. when the fully potted plant pot is placed inside the plant pot container.
A Level Indicator is a common tool found with hydroculture. While it is not absolutely necessary, adding a Level Indicator will prevent many mistakes and take some of the labor out of checking the Water solution.

No comments:

Post a Comment