Get Into Hydroponics
By John Mason
Hydroponics doesn’t have to be complex; in fact, you can do it without pumps, power or expensive equipment. A small manual system involves a little more work, but it can be a lot easier to get started this way.


Why grow in hydroponics
For some, it’s just another thing to try, but there are other reasons:
• People with limited mobility (disabled or elderly) can continue gardening in hydroponics when their physical condition may have stopped them gardening in the soil.
• Pests and diseases can be more easily controlled.
• It allows more possibilities in a smaller space (even a small balcony can be turned into an abundant hydroponic garden).
• Hydroponics can be environmentally friendly, if done properly.

What is hydroponics
Hydroponics is simply growing plants without soil.
Soil provides four main things to a plant: root protection, foliage support, water and nutrients.
With hydroponics plants still receive these essentials,
-Roots are protected from drying out by enclosing them in either a clean medium (eg. Sand) or a humid environment (eg. A pipe).
-Support is provided by tying plants to a stake or just letting them “flop” on the surface (depending on the variety).
-Water and nutrients are provided as a specially formulated solution.

Difference between Manual & Automatic Systems
Automatic systems use pumps; time clocks and sensing devices to “automatically” move nutrient solution to the plants as required.
Manual systems depend on you to check on the plants and periodically add nutrient solution as required.

A hydroponic system comprises the following components:

The Location
This is a KEY FACTOR, because it influences everything else.
*If the system is indoors, then the environmental conditions are under control. The temperature will fluctuate less than outside and wind may be reduced.
*If the system is outside it will be exposed to rain that may dilute the nutrient solution, and wind which may stress the plants.
*Pest and disease problems (including cats and dogs) are reduced by keeping the system isolated indoors, or raised off the ground.

The Container or Bed
The roots (as well as the nutrient solution and medium) need to be contained in something.
*You may have gravel, sand or perlite in bags, pots or tubs.
*You may have rockwool fibre or scoria contained in a raised bed built from timber, metal or concrete.
*You may use polystyrene boxes, hanging baskets, prefabricated fibreglass tanks and so on. The list of possibilities is endless.

Watering/Nutrient Application Equipment
*Nutrient can be applied dry on the surface and then watered in, or mixed with water and applied as a nutrient solution.
*Solution may be applied automatically at predetermined times, or as required.
*It may be applied at the bottom of the media and allowed to move up via capillary action, or alternatively at the top and allowed to filter down.
*It may be pumped on, moved manually, or by gravity.
*Excess may be collected and reused, or allowed to be lost after passing through the media.

Trellising
This is not included in all hydroponic growing systems.
When growing tall plants or creeping plants (eg: Tomatoes, cucumber, Chrysanthemum, Carnation, Roses etc), the root medium may not be strong enough to support the plant, or it might be necessary to control the plant.
A trellis of wire mesh, strings or stakes may be necessary to just prevent the plants from falling over and being damaged.

Root Media
The media which the roots grow in affects your decisions about all of the above. You must consider rooting media with respect to its ability to hold water, air, nutrients, support the plant and so on. This is also done by considering the type of plant you are growing – each type of plant has different requirements.

A simple system to start with
A container (eg. A large plastic pot; a trough or a polystyrene box) is filled with a medium such as coarse sand, or perlite. The medium is thoroughly watered with a nutrient solution.
Buy one or more parsley or silver beet plants. Remove them from the pot, and wash all the soil from the roots.
Plant the bare rooted plants in the container. Water with nutrient solution whenever the medium is starting to dry out. In hot weather check regularly –you may need to water daily. In cooler weather, watering weekly may be more than adequate.

What about nutrient solution
Hydroponic nutrient solution is different to normal fertilizer (it contains calcium, magnesium and trace elements in quantities not found in most garden fertilizers).
You can buy Hydroponic Nutrient from some garden centres. Most should be able to get it in for you if you ask. You can also get it from Hydroponic shops.

Water less often
*When you apply nutrient solution, you are watering and feeding at the same time.
*If the medium holds water better, you don’t need to water as often.
Increase the medium’s water holding capacity by using more absorbent material like rockwool, perlite or vermiculite, rather than sand or stone chips.
Reduce the rate at which water is lost, by shading or covering the medium –put a sheet of black plastic over the top (cutting holes for plants to poke through) or stand in a saucer of water.

What to grow
You can grow just about anything in hydroponics, from vegetables to berries, and flowers to indoor plants.
Some plants are a little easier to grow in hydroponics than others though; and for the beginner, it is often best to start with things that are tried and proven hydroponic crops such as leafy vegetables (eg. Lettuce, silver beet), strawberries, tomatoes or cucumber.

What can go wrong

Too much salt
When white powder forms on the surface this is probably salt residue from unused and unwanted parts of your nutrient solution. When this appears, it’s a good idea to wash the whole system through with water, let it partly dry for an hour, and then add fresh nutrient solution.

Nutrition : too much or too little
Use a properly formulated hydroponic nutrient solution (bought from a nursery or Hydroponic shop), and the chances of a serious problem are rare. Toxicity is less common than deficiency.
The following do sometimes occur:

Nitrogen
Yellow foliage or simply very slow growth, is most likely when weather conditions favor rapid growth, and you are simply not supplying nutrients fast enough.

Iron
Iron deficiency shows as yellow growth tips, and is common under cool growing conditions, where the root system might have become saturated, damaged or where the ph is running high.

Phosphorus
A phosphate deficiency will cause the roots to become brown with a reduced number of lateral branches. A lack of calcium will induce a thin, poorly developed, brown root system.

Magnesium
Magnesium deficiency on crops such as tomatoes can be induced by high levels of potassium uptake.

Calcium
Calcium deficiency

which shows as tip burn on lettuce and blossom end rot of tomatoes and peppers. It is a calcium transport problem within the plant, rather than a lack of calcium in the solution. It is induced by environmental conditions such as high humidity, which restricts transpiration and calcium distribution.

Other Deficiencies
Manganese deficiency will cause a small root system that is much shorter and finer than usual, with some browning of the root tips. Copper deficiency results in severe underdevelopment of the root zone. Boron deficiency causes the root tips to become jelly-like in appearance.

ALGAE
Most hydroponic growers come across algae sooner or later. Algae don’t directly kill plants, but it can cover the surface of the media, or block drains or irrigation pipes, impairing water flow.

PESTS AND DISEASES
Plants can suffer from pests and disease in hydroponics as much as in soil; but in theory, a hydroponic system can start out cleaner and may be kept clean easier. A well managed hydroponic system usually has fewer pest and disease problems, which means less need for chemicals, and less contaminated produce.
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