A deep water culture is one of the simplest and most effective hydroponic systems. In this design each plant grows over a large (and deep) reservoir. The roots dangle into the nutrient solution in the reservoir below.
This is one of the simplest designs that you can build at home. A mason jar filled with seeds or one 5-gallon bucket with a small air pump will get you started!
All plants need a fertile foundation to thrive. In the traditional farm or garden setting, plants get their nutrients from soil that can contain additives such as compost, manure, or chemical fertilizers. Again, hydroponics is completely soil free, so nutrients are delivered directly to the plants through the solution with which they are watered.
Calibrating the nutrient solution increases plant growth. The pH and electrical conductivity (EC) of the water fluctuate as the plant grows and consumes nutrients. For this reason, keeping consistent tabs on the nutrient solution ensures that it stays in the best range of the crop. The deep water culture system makes the replacement of the nutrient solution simple and minimal. Simply drain and re-fill.
Single DWC buckets are difficult to maintain as production is scaled up. As a result, this has led to the creation of Recirculating Deep Water Culture (RDWC) systems. An RDWC features individual buckets for each plant interconnected with series of PVC pipe. A separate control bucket holds the bulk of the nutrient solution. This allows the operator to test for pH and EC at an individual location for multiple plants. To aerate the nutrients, a pump pulls water from the rear of the system into the control bucket and may cycle through several times.
Moreover, RDWC can be customized in several different formats depending on the number of individual buckets and space provided. It saves time and supports a consistent nutrient solution for many plants.
It is not all sunshine and roses. There are some issues with a deep water culture system that can cause problems, but they are all avoidable if maintenance is consistent.
All said, the positive benefits outweigh the issues. A deep water culture system is easy to assemble and versatile with styles ranging from counter-top systems to larger set-ups for commercialization. The expedient nature of growth offers quicker harvest times as well as the ability to produce all year long.
Do not let the simplicity of this design fool you. We have grown large tomato plants in a simple 5-gallon bucket.