Maximum Yield USA 2015 December | Page 72

WHAT IS A DWC SYSTEM? Recirculating Water Culture Systems Another variation of the typical water culture system is a recirculating water culture system. The recirculating system works like a flood and drain system, but it never drains. You can have as many growing containers (reservoirs) as you want connected to one central reservoir. Each growing container has its own fill line, as well as a drain/overflow tube that drains back to the central reservoir. Some growers use buckets instead of wide, shallow containers. Each bucket has its own plant in it and is filled with nutrient solution. A lot of systems feature a row of these buckets and use a fountain/pond pump to pump the nutrient solution up to each of the buckets. As the water fills the buckets, the excess water spills over into the overflow tube and flows back to the reservoir, where it’s recirculated back through the system again. Most growers who recirculate the nutrient solution like this in their water culture systems only use an air pump in the central reservoir, rather than in each individual bucket, to save money. They also let the water pump run 24/7. However, if you have air bubbles running in each bucket, you can vary the ON time for the water pump, and the plants will benefit from having direct contact with the rising air bubbles contacting the roots. 70 Maximum Yield USA  |  December 2015 “THE RECIRCULATING SYSTEM WORKS LIKE A FLOOD AND DRAIN SYSTEM, BUT IT NEVER DRAINS.” Recirculating the water allows you to use falling water as a source of aeration in the system. You also won’t need to keep checking the water level in each container to replace the water the plants drank up—you just check and replace it in the central reservoir. This is a nice benefit when you are growing large plants, or many plants in the same system. In fact, just about all of the large, commercially operated water culture systems recirculate water through the system. For more information on building and maintaining a water culture hydroponic system, visit h