The choice of growing medium will depend largely on the type of hydroponic system used. If a aeroponic is used the growing medium need not retain water, but generally the ideal hydroponic medium for most systems should hold equal parts oxygen and water. This allows the plants to have access to both the water and oxygen at all times.
Clay Pebbles for Aeroponic Systems
Clay Pebbles are also called grow rock. Clay pebbles work very well in aeroponic systems, but if another type of hydroponic system is used they should be combined with another growing medium because they do not retain any water on their own.
Coconut fiber
Shredded coconut fiber makes for a very good growing medium. It can be used on its own but it is commonly mixed with other medium such as perlite or rockwool.
Hydroponics with Perlite
Perlite is inexpensive and is a very good growing medium. It doesn't retain too much water and is very porous, allowing the plant to get a good mix of water and oxygen. Some people like to mix it with vermiculite which gives the mixture more water retention.
Vermiculite Growing Medium
A rather unhealthy choice of growing medium since it can contain small amounts of asbestos. Indoor gardeners need to wear a mask when handling vermiculite because of the health risks associated with asbestos. The reason why growers like to use vermiculite is because of its good water retention and availability. It is often mixed with perlite.
Hydroponic Gardening with Rockwool
Rockwool is probably one of the common growing mediums used today because of its high water retention capabilities. The nice thing about rockwool is that it can't be over-watered because it also very airy. It has been said that rockwool can hold 10 times as much water as soil. Rockwool can be reused over and over again and is therefore an ideal choice of growing medium for the indoor gardener.
Nutrients for Hydroponics
While there are many types of growing systems, the two most popular growing media today are rockwool and perlite. Since the growing medium does not, in itself, give the plant any nutrients like soil would for plants grown the conventional way, a lot of attention needs to be given to the nutrients given to the plants in the water.
Careful consideration should be given to the type of water used in the hydroponic system, since high quantities of chlorine, fluoride and sodium can adversely affect the plants. Some countries put excessive amounts of chlorine and fluoride into municipal water. In such cases, rain water can be collected for use in the hydroponic system. Another alternative to tap water is bore hole water as long as the water is not too salty.
Hydroponic systems can be more efficient than traditional growing if attention is given the the growing medium used in the system and the nutrients used to feed the plants.
Related Articles on Hydroponics
Why Grow Plants with Indoor Hydroponic Systems? - Examines the advantages of hydroponics.
How to Create a Hydroponic Garden - Methods of building a simple ebb and flow system.
An Introduction to General Hydroponics - A brief discussion of the different kinds of hydroponics systems available
Fleur Hupston - Fleur Hupston is a professional freelance writer based in Botswana, Southern Africa. From this unique perspective, she writes travel ...
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