Garden & Greenhouse July 2017 Issue - Page 10

The major advantage of a DWC system is the tremendous speed of plant growth due to the read- ily available nutrients and oxygen in the root system. The biggest disadvantage of a DWC system is suscep- tibility to temperature fluctuations. Because the roots are submersed in the nutrient solution, warm water temperatures will deplete the amount of oxygen available to the roots (even with an air pump supply- ing aeration). Smaller deep water culture systems (1 - 6 buckets) are great for experimentation because they are relatively easy to maintain. However, gardeners looking to set up more than six modules should plan on purchasing an industrial air pump and a water chiller to maintain cooler temperatures and maximize dissolved oxygen around the submersed root mass. Top Feed Top feed hydroponic systems are systems where the nutrient solution is delivered from the reservoir to the base of each individual plant via a feed-line. The main reservoir generally houses the submersible pump which is connected to a main-line. Once the main-line is pressurized, it pushes nutrient solution through each feed-line. Top feed systems can be set up as either a run-to-waste or recirculating system; the latter being the most efficient option. Plant mod- 10 ules for homemade top feed systems can be built from buckets, yogurt containers, plastic cups, or just about anything else that can hold water and medium. A common solution for a homemade reservoir is a large Rubbermaid® container or a feed trough. Be sure to get the right size pump for the job. This will be determined by the length of the main-line and the amount of feed-lines needed. Ebb and Flow Ebb and flow, also known as flood and drain, hydroponic systems rely on a reservoir, a trough or table, a submersible pump for water delivery and an overflow drain. Ebb and flow systems are very ef- ficient systems and are easy to build and maintain. Simply put, they are a great choice for greenhouse hobbyists looking to experiment with hydroponics. The table or trough for a homemade ebb and flow system can be made from wood and pond liner and the reservoir can consist of a large Rubbermaid® container. The submersible pump delivers the water to the table or trough for a given period of time. After the pump turns off, gravity returns the nutri- ent solution back to the reservoir for later use. There are many different ways to set up an ebb and flow system and many different materials that can be used www.Garden