“Ebb and flow” hydroponics system is an example of the common arrangement of the indoor garden. Such system is composed of the upper grow bed, which is a box or tray that holds containers with plants. Those individual containers may be filled with various mediums, the most frequently used ones being rockwool, coconut fiber, lava rock, perlite, vermiculite or styrofoam pellets. The best mediums are those that are porous and can accumulate some water for a long time: lava rock is said to be the best in this respect.

The other part of the hydroponic system is the lower bed – the reservoir with the mix of water and nutrients dissolved in it.  Aquarium pump, regularly triggered by a timer, sends water solution up into the tray with plants.

The most important thing is to keep the correct composition of water solution in the reservoir – this is the key factor of the hydroponic garden flourishing. Many beginners find it difficult to maintain the right pH level of the water, necessary amount of nutrients, and their correct ratio. 

Standard organic nutrients are available to fertilize plants; however, many people are reluctant to do that, as they think such fertilizers will quickly make the water reservoir dirty. Indeed, organic nutrients interact with the organisms in water, which leads to their decomposition. Specialized concentrated nutrients, on the other hand, keep the reservoir relatively clean, since they are synthetically made and thus they cannot interact with the organisms in water. Nonetheless, such “clean” fertilizers will severely burn the plants roots if used in access.

Being pumped into the grow bed, water with a fertilizer saturates the plants and returns to the reservoir lacking the previous amount of nutrients and ppm (parts per million). Thus, its composition is always different and changeable. That is why a gardener should always monitor water solution, controlling its pH level and plant nutrients amount.