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W H A T I S H Y D R O P O N I C S ?
Hydroponics is the cultivation of plants without soil.
Hydroponics is not new technology. The history of
hydroponics dates back to the famed Hanging Gardens of
Babylon, one of the Seven Wonders of the Ancient World,
and in the 1990s, NASA grew aeroponic bean seedlings
in zero gravity aboard a space station, opening up the
possibility of sustainable agriculture in space
Hydroponic flowers, herbs, and vegetables are planted in
inert (soil-less) growing media and supplied with
nutrient-rich solutions, oxygen, and water.
Common growing media includes coco husk, rockwool,
clay balls, perlite, vermiculite, and even without any
growing media. This system fosters rapid growth, stronger
yields, and superior quality. When a plant is grown in soil,
its roots are perpetually searching for the necessary
nutrition to directly to water and nutrition, the plant does
not have to exert any energy in sustaining itself. The
energy the roots would have expended acquiring food and
water can be redirected into the plant’s growth. As a
result, leaf growth flourishes as does the production of
fruits and flowers.
It is common for hydroponic growing systems to be
located within a greenhouse structure. This allows for
the additional benefit of being able to control air
temperature, humidity, shading and even lighting. It also
has the added benefit of protecting the plants from the
outside weather elements and providing minimised pest
problems and ease of pest control.
Introduction to Hydroponic Systems
Fired clay balls (left) and perlite-vermiculite mixes (right) are common inert growing mediums in hydroponics.
Tomato seedling in a cocopeat filled bag (left) and ready to use hydroponic blocks (right).
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T H E B E N E F I T S O F H Y D R O P O N I C G R O W I N G S Y S T E M S
■ Can grow more produce per square meter of
ground
■ Potential to use up to 90% less water than the
same plants grown in the soil
■ Can have total control over the type of, and
amount of nutrients the plant gets
■ Can grow crops faster
■ Plants are free from all soil borne pests and
diseases
■ Extended growing seasons if grown within a
greenhouse environment
H O W D O E S A H Y D R O P O N I C S Y S T E M W O R K ?
Hydroponic systems work by allowing maximum control
over environmental conditions like water quality and
nutrients. Hydroponics operates under a very simple
principle: provide plants exactly what they need when
they need it. Hydroponics administer nutrient solutions
tailored to the needs of the particular plant being grown.
Water quality can be monitored and adjusted, and in a
highly customized and controlled environment such as
this, plant growth accelerates.
In simple terms, hydroponic systems have a water tank
containing the nutrient solution, which is then pumped to
the root system of the plants, with many systems having
the unused nutrient solution returned to the main tank.
See below for an overview of the main types of
Hydroponic growing systems
C O M M O N T Y P E S O F H Y D R O P O N I C G R O W I N G S Y S T E M S
N F T ( N U T R I E N T F I L M T E C H N I Q U E )
NFT is a hydroponic technique where a very shallow flow of water (2-3mm), containing all the dissolved nutrients
required for plant growth, is recirculated past the bare roots of plants in a watertight chamber known as a gulley
or channel. Aeration (oxygen supply) is provided passively due to the depth of water in the gullies and can also
be supplemented via an air pump in the reservoir tank. This growing method is common for plants such as
lettuce, Asian greens, herbs, and even seedling production
See fact sheet 2.102 Nutrient Film Hydroponic Systems for further information
Bok choy growing in a Food Ladder hydroponic system.
A flood and drain system growing lettuce.
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F L O O D A N D D R A I N T E C H N I Q U E ( E B B A N D F L O W )
Flood and drain (also known as ebb and flow) hydroponic systems work by flooding a grow bed or trough from a
tank filled with nutrient solution. The pump is on a timer that fills the trough several times per day, with the excess
nutrient solution draining out and being returned to the nutrient tank for re-use.
The troughs contain a free draining growing media that can support the root system of the plants, retain moisture,
and allow high levels of aeration. Clay balls (hydroton) and pumice are the most common growing media used,
but a mix of sand, perlite and vermiculite can also be used.
This growing method is common for plants such as lettuce, spinach, salad greens, cabbages, Asian greens,
strawberries, chillies, and herbs.
See fact sheet 2.103 Flood & Drain Hydroponic Systems for further information
D R I P S Y S T E M ( M E D I A F I L L E D B A G S )
In a hydroponic drip system, the aerated and nutrient-rich water tank pumps the solution through a drip irrigation
system to individual plants. Regulated emitters and drip spikes feed nutrient solution into the growing media
surrounding the root system, keeping the plants moist and well-nourished. Plants are irrigated for short periods
several times a day keeping the media moist, but minimising run-off. Some systems are designed to return run-
off water to the nutrient tank, whilst others have any excess water run to waste.
The bags can be purchased (as blocks) ready to use generally containing cocopeat or rockwool, or plant pots
and bags can be used that you fill yourself with course cocopeat.
This growing method is common for plants such as tomatoes, cucumbers, eggplants, capsicums, berry crops and
other larger crops.
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D E E P W A T E R C U L T U R E
Deep water culture hydroponics are simply plants suspended in aerated (oxygenated) water. Deep water culture
systems, also known as a DWC system, are one of the easiest and most popular methods of hydroponics on the
market. A DWC system dangles net pots holding plants over a deep reservoir of oxygen-rich nutrient solution.
The plant’s roots are submerged in the solution, providing it with constant access to nutrition, water, and oxygen.
Deep water culture is considered by some to be the purest form of hydroponics. This growing method is common
for plants such as lettuce, Asian greens, and herbs.
A Q U A P O N I C S
Aquaponics is a modified version of hydroponics that can be used for the 4 hydroponic growing systems
described above. With aquaponics, the nutrient solution tank is replaced with an open tank containing fish. The
waste from the fish in the tank water is used as the nutrient to feed the plants, with the plants filtering out all of
the nutrients leaving clean water to return to the tank. The farming of fish is quite intensive and requires
additional levels of water filtration and management, as well as looking after the fish.
S O U R C E S
Scott McDonald, Horticulture & Training Manager, Food Ladder
https://www.freshwatersystems.com/blogs/blog/what-are-hydroponic-
systems
“Gardening Basics Hydroponics” KidsGardening.org
D I S C L A I M E R
© Food Ladder, 2020
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2.102 NUTRIENT FILM
TECHNIQUE
2.103 FLOOD & DRAIN
HYDROPONIC SYSTEMS
2.104 HYDROPONIC DRIP
SYSTEMS
2.105 HYDROPONIC PLANT
SELECTION & GUIDE
W H A T ’ S N E X T ?
