Disadvantages of E&F-Systems

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Ebb-and-flow systems are very flexible and show only a few practical disadvantages. Although these systems generally are used for the compact cultivation of smaller plants, they are also used for big plants. In this case they use buckets with a capacity of 1 to 5 liter. Here the application of high-performance pumps is required that are also used for big aquariums, decorative wells or koi-ponds.

Nachteile E&F-Systeme

These systems have some similarities with the one of large applications concerning the work effort: In the first place the handling of the mediums between the utilizations, e.g. the cleaning and sterilization. This can be done by using a sterilization solution like e.g. hydrogen peroxide. The process is temporarily turned on and root fragments are removed by hand. When bigger containers are used, it is required to put the medium on a proper surface after the sterilization process, to remove the remaining plant material.

Another disadvantage is, that the roots tend to grow together. This means, that the removal of harvested or damaged plants can be problematic, because the roots have a well-developed root system. Indeed, this is not a problem for commercial agricultural crop, where all plants are harvested at the same time, but instead a massive risk of a disease infestation can occur. Since all roots are flooded out of the same source, germs can spread out very fast.

Most ebb-and-flow systems use a reusable reservoir to flood the table. During a certain period, it can occur, that due to up and downturns the pH-value of the nutrient solution can reach a range that is not healthy for the plants. If the pH-value is at a wrong level, there are several different problems that can occur, for example nutrient absorption and leaf-cannibalism. Leaf-cannibalism occurs when a plant absorbs the nutrients from a plant part and uses them for another part. This is visible through brown spots on the leafs.

Bad or incomplete drainage can lead to a condition, where close-grown roots are exposed to standing water which accumulates to get into the dense root-system. Standing water mostly results in root rot, or the development of fungi. Some E&F systems are not composed that well to prevent root rot. If the tables carry plants, which exceed the, for the system optimal size, modifications become necessary - e.g. the implementation of beds with mid-coarse gravel, to prevent standing water. The tilt of the tablets to one side is also an option to achieve better drainage. With E&F systems that use buckets, this problem can be solved likewise by choosing the right size of the medium. Furthermore, it is important to secure a complete drainage between the flood-cycles.

If the suspicion exists, that the anaerobe Pythium root rot already exists at the root-surface, hydrogen peroxide can be added to the nutrient solution. The oxygen that is released from the hydrogen peroxide affects monocellular organisms destructive. The doses can vary depending on the concentration of the peroxide. Typically, of a 3,5% solution some teaspoons are added per one gallon. The rapid increase of oxygenation damages the roots only a little, whereas the elimination of water molds can boost the harvest immensely, or even secure the survival of a cultivated crop.