Deep water culture has been around for some time now and continues to gain more and more ground as a direct result of its consistent profits and effectiveness. When done correctly, many growers feel it is an unbeatable way to grow.
For those of you who are transitioning from beginner to intermediate, or for more advanced growers looking for a boost, DWC might just be your golden ticket. We caught up with Daniel Wilson, a long-time guru of the trade, who shared his tips on starting up a deep water system.
DWC is a method of growing in which plant roots are suspended indefinitely in a large volume of nutrient-rich, oxygenated water, which naturally improves a plant’s ability to uptake nutrients more efficiently, explains Daniel. DWC incorporates the use of air pumps and air stones that run continuously to compensate for the oxygen the roots aren’t getting from the air. Let’s take a closer look.
Oxygenation in a DWC System
DWC systems require a lot more oxygenation than other methods of growing. By introducing increased levels of oxygen into the reservoir, aerobic respiration takes place. Aerobic respiration is an important process that releases the energy required to carry out nutrient uptake and root growth. If this process is inhibited by a lack of oxygen, subsequent plant stress is likely to occur.
Using a combination of air pumps and air stones is the most popular way to bring increased levels of oxygen into the reservoir. Some people choose to use air pumps alone, as they produce bubbles without the use of air stones.
However, Daniel recommends using air stones in conjunction with air pumps, as the porous surface of the air stones rapidly forces many tiny, oxygen-rich bubbles into the environment, distributing oxygen more evenly throughout the entire solution. This also expedites the process of dissolving the oxygen into the solution, as many tiny bubbles are able to permeate through the solution faster, covering a lot more surface area than larger bubbles alone.
Nutrients in a DWC System
As with other hydroponic systems, it is important to monitor your DWC garden’s nutrition program. “When the nutrient solution is well-managed, plants are better able to metabolize the water and minerals in the solution for photosynthesis,” explains Daniel.
Fortunately, DWC systems make effective use of the nutrients supplied. “Whether you’re interested in conserving the planet’s natural resources, or simply just conserving the contents of your wallet, DWC provides increased productivity and faster growth, which equates to a more efficient use of resources,” says Daniel.
One way to optimize nutrient uptake in a deep water environment is to use multi-part nutrient blends. Some folks prefer to use as few products as possible, so they will go with one-part nutrient formulas in an effort to save money, but in the long-term, this is not recommended in DWC systems.
“Using incompatible inputs in solution may cause convolution of the water chemistry,” explains Daniel. Multi-part nutrient blends, with stage-specific mineral ratios, are best-suited to maximize growth in a deep water environment.
This is particularly important because the roots are exposed to the nutrient solution at all times, so they might absorb these nutrients selectively as they need them, which theoretically should be proportionate to the nutrient grade being used, dependent on the stage of growth.
Using products that are renowned for their high-solubility ratings will give growers a more successful experience with DWC. “Water culture works best when growers avoid organic, low-solubility inputs,” says Daniel. For those of you who choose to use products of lower solubility, it is important to compensate for the negative effects you may encounter.
Hypochlorous acid (HOCl) is a mild oxidizing agent that many growers use to maintain their systems at optimal conditions. HOCl will work continuously to break down harmful scale and biofilm, which are compounded by low-solubility products.
Water that has been treated with HOCl also reduces the risk of developing problems such as root rot that are often associated with overwatering and insufficient oxygen levels. Many growers will use it as a part of their regular regimen as a sort of insurance to maintain a healthy growing environment.
Stability in a DWC System
Stability can mean a few different things when it comes to DWC. First and foremost, because plants typically grow much larger early on in DWC compared to traditional hydro systems, it is important to set up a support system such as trellises or tomato cages to prepare for the extra height and weight your plants will quickly grow into. The last thing you want is to grow the biggest plants of your life only to have them topple over in the night due to excessive weight. Setting up supports early on is a quick fix that will help save you a headache later on.
Another thing to be mindful of is keeping your pH levels stable, without micromanaging. “Adjusting pH too frequently can lead to nutrient solution instability and other related issues,” says Daniel. “As with most things in life, it may be best to stick with the ‘everything in moderation’ principle on this one. As a general rule of green thumb, try to maintain a harmony between target EC and pH values, but don’t necessarily expect the numbers to be within minute, fractional units at all times.”
There are a variety of options and many things to learn as a novice DWC-er. While some DWC systems may require higher levels of investment, you will quickly reap the rewards if you are devoted to their successful operation. Use this advice as a guide to starting something new. You won’t be disappointed.