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.
Drip System
- This method is probably the most widely used type of
hydroponic system in the
world. Operation is simple; a timer controls a submersed
pump. The timer turns the pump on and nutrient solution is
dripped onto the base of each plant by a small drip line.
In a Recirculating Drip System the runoff is collected
back in the reservoir for re-use. In a Recirculating Drip
System the runoff is collected back in the reservoir for
re-use.
The Water-to-Waste System does not collect the runoff. The
advantage of Water-to-Waste is that the nutrient solution
in the reservoir has never passed through the system, so
it is unchanged. In a Recirculating System, the nutrient
solution can fluctuate in both nutrient concentration
levels and pH levels.
We recommend a soilless
mix for Water-to-Waste systems, because soilless mixes
retain more water. This way, the pump kicks on less often,
so you use less nutrient solution. With quality nutrients
and a good soilless mix, a Water-to-Waste Drip System can
be one of the best ways of gardening with lights.
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.
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