Here is a pic of a drip system w/ circular emitter ring (Waterfarm by Genl Hydro). It is v similar to the Genl Hydro Aquafarm I used 20 yrs ago. The nutrient solution comes out of the holes in the circular emitter ring. The air pump at bottom left is kept on 24/7 and it brings air down the center of the module to the water which then bubbles, saturating the roots with oxygen. When I used this type of system, I connected eight modules together with that blue tubing you see. They then fed into a 4-gal controller with a float valve. I then placed a 32-gal plastic trash can on top of the 4-gal controller which served as a top-off reservoir.
The growth rate was so intense that it didn't make sense to go beyond two weeks in the grow phase. We learned our lesson the first time we used it when we went four weeks in the grow. The project was aborted in the fifth week b/c it was evident we'd be dealing with 7' tall plants (Super Skunk and Big Bud, both from Sensi Seeds). So from then on out we used a two-week grow w/ a nine-week bloom which was perfect.
Current Culture, which seems to be
the hydro system of choice for commercial cultivators, has taken this basic concept (DWC) and expanded upon it. I look forward to using their Under Current product. Instead of Gavitas, I intend to use the Boulder Lamp 315w CDL Agro made by Philips (ballast and hood by Boulder, lamp by Philips). These draw 315w and put out the equivalent of 600w of light. The light spectrum is mint. Boulder says this is the coolest-temperature light around, even cooler than LEDs.
I also intend to use the new dissolved-oxygen product by O2 Grow (it is not on their site yet). With one emitter in each module replacing the standard air stones that come w/ the Under Current system, dissolved oxygen should go up somewhere around 50%, from 8.5 ppm to about 12.5 ppm. On the O2 Grow site, it shows where Univ of Tenn and Univ of Minnesota increased their vegetable yields by 13% to 58% using the O2 products. Wow!
