The irrigation water of hydroponic systems must be filtered to keep foreign objects out of the system. Open systems are relatively easy to filter since the water moves in one direction, so it is used only once. With closed systems the situation is entirely different. Not only is the water polluted with organic material from [...]
The correct gravel depth is important for the development of the roots system. Too shallow gravel will not only restrict root development and volume, but will also cause the development of algae on the surface of the gravel. The algae attract fungus gnats which feed on the roots of plants. The reason why the gravel [...]
The following procedure should be followed when mixing fertilizers in nutrient tanks: Fill the tank with water Check if the pH is between 5.5 and 6.8 Increase or decrease the pH if necessary with either an acid or base Start stirring the water in the tank. The water in the tank can also be agitated [...]
The basis on which to choose a small nutrient tank or large nutrient tank will be: The relative volume circulating at any given time in the whole systemThe rate at which the solution formulation must be changedThe estimated risk that diseases can enter the system and how effectively it can be controlledCapital availableAmount of water [...]
Hydroponic nutrient tanks can be made from any type of material as long as it does not react or cause a reaction with the nutrient solution. For instance, galvanized tanks are not suitable if the nutrient solutions come in direct contact with the metal. If galvanized tanks are used, the plants will show a Zn [...]
Plastic gullies (or also called hydro-liners) are made from thick durable plastic with a thickness between 125 micron and 500 micron. The recommended thickness to use is the 500 micron plastic. Although it is much more expensive, it is also more durable especially during the building phase where people tend to walk over the plastic [...]
Over the years, closed hydroponic systems have been criticized quite often for their high initial capital cost and the perception that these systems have a high disease risk. During the initial development of the closed system in 1961, these criticisms might have been true since little scientific knowledge was available. Since 1961 an enormous amount [...]
