All DWC systems have the same requirements, though they achieve them with different components. The main thing to remember is that each system completely submerges the roots in the nutrient solution and that aeration is essential to keep the roots from dying. Air stones are the most common way to aerate your plants but alternate methods like sprayers or waterfalls will work. To tell if you’ve added enough oxygen to your solution, a good rule of thumb is to make sure you see bubbles appearing over 1/3rd of the surface of the water and leave the aerator running 24/7. Since the aerator needs to run constantly, you need to make sure that someone checks for power outages or breaker trips regularly.
Plant Tray/Support
Variants
The easiest and most popular DIY method is just a standard bucket. Quite literally, a black bucket with an air stone inside. The plant is nested in the lid of the bucket, typically using some kind of basket or cup, and the nutrient solution level is raised up to the level of the roots (do not immerse the stalk). A hose connects an air pump to the air stone and forces air through it to add oxygen to the water. Depending on the size of the bucket, this works for either one large plant or a few very small ones.
The second method is a little more complex but has the advantage of increased growth during the first few weeks. Bubbleponics uses an additional water pump to push the water above the roots and let it flow back down over them. The rest of the system is similar in that the reservoir contains an air stone and an air pump to keep the water oxygenated, but the water itself is cycled to feed the roots from above so the roots are covered in water from day one.
More complicated is the re-circulation DWC system. This uses multiple buckets connected to a large reservoir. Each bucket is filled with a system of sprayers. By spraying the water into the buckets, it adds oxygen and agitates the water to keep it circulating. No air stone is needed but it requires more piping and parts than either of the other two systems. And the multiple buckets allow you to grow more plants in the system.
