Definition - What does Closed System mean?
In gardening, a closed system refers to a hydroponic system whereby the same nutrients or nutrient solutions are repeatedly recycled. This differs from other types of systems whereby fresh solution has to be re-applied often.
A closed system is a cost-effective system that is ideal for larger crops. However, the concentration of the nutrient solution needs to be regularly monitored and adjusted accordingly.
MaximumYield explains Closed System
The term closed system is applied to various types of hydroponics. Nutrient film technique (NFT) hydroponic systems, for instance, use a non-stop flow of nutrient solution around the roots. This provides the plant with continuous access to nutrients and aeration alike. Rather than drain to waste, the nutrients are constantly being recycled within the closed system.
The ebb and flow hydroponic technique is another method of hydroponics that is commonly used in a closed system. Extremely low-cost and low-maintenance, this technique works particularly well with potted plants and plug production. The ebb and flow closed system, sometimes referred to as flood and drain, entails a pump and nutrient reservoir flooding the plot of grow media and allowing the nutrient solution to drain away to waste or to a nearby reservoir. The frequency of this action within the closed system depends on a number of factors, such as the plant’s water requirements, the size of the growing containers, as well as the type of growing medium.