Any aquarium supply store will stock many different sizes of pumps and stones (or wands). The finer the size of the air bubble, the more oxygen is absorbed by the roots, so find airstones that spread a mist as widely as possible. As with good champagne, what you're looking for is "tiny bubbles." Fill the bucket with nutrient solution and make sure the airstones sit on the bottom while bubbling, weighing them down if necessary. Early in life, when roots are young and short, the nutrient level should reach the bottom inch of the grow cup. As the plant grows, the level should drop several inches; the explosions of the many bubbles as they reach the surface will keep roots at air level sufficiently moist.
A controller bucket, containing pH-balanced solution but no plants, manages nutrient levels when using more than one container. The solution in the controller bucket flows by gravity to fill the individual buckets as the plants absorb their liquid food. Under hot lights, evaporation is also an important factor. Full-sized pot bushes in DWC systems can use up solution by the gallon daily, so careful monitoring is in order: Dry root systems cause massive problems quickly and, ultimately, plant death.
Deep Water Culture is a great way to grow a lot of pot in a relatively small space. DWC systems are also easier to pack up and move than a traditional hydro table or PVC tube set-up-no small consideration for those who may need to let landlords, meter readers or building inspectors visit on short notice.
Root diseases and plant viruses can also be isolated in the affected plants, saving the remaining plants from demise. DWC systems are easy to build but, for those less mechanically inclined, commercially available systems like the Waterfarm units from General Hydroponics can be converted to take advantage of DWC combined with their existing drip-system technology.
Hydro growers interested in huge yields with fewer hassles should look into using the DWC technique. Super-oxygenated roots promote rapid growth and healthier, happier bud bushes. For the cost of a few buckets and some aquarium equipment, cannabis cultivators will be bubbling over with pride at the sight of their enormous pot plants.