If you are an enthusiastic cannabis grower, and have considered switching to a hydroponic setup then you have probably heard of the deep water culture (DWC) technique. This popular method of hydroponic cannabis cultivation has received a lot of positive feedback from growers who have tried it. One of the main benefits of hydroponic cultivation is that water is a much more efficient medium than soil or coco coir for delivering nutrients to the root zone of your cannabis plants.
DWC is just one system for hydroponic growing, but it has the dual advantages of being easier to setup than other hydroponic systems, and requires less maintenance over the lifetime of your grow. Due to hydroponic’s more efficient uptake of water and nutrients by your plants, you can improve both the quality and quantity of your buds. Additionally, hydroponic systems speed up the growth cycle of your plants, reducing the vegetative and flowering periods, making it quicker to go from seed to smoke.
Interested? Then keep reading to get all the details on DWC.
What is Deep Water Culture
This hydroponic based planting technology utilizes water as a medium for the plants roots instead of soil or coco coir. The deep water in deep water culture comes from the fact that the roots of the marijuana plant are supplied with a large volume of water to grow in. This liquid is composed of highly aerated water which has been fortified with the nutrients that your plant requires to grow.
Plants are suspended above the nutrient solution, and roots are allowed to grow down into the water which allows for absorption of nutrients.
So why is the dwc method ideal for cannabis cultivation?
There are a couple of advantages to growing cannabis using this method. One of the advantages of hydroponics in general is that all nutrients within the system are always available to the plants, and using tools such as EC and PH meters, the grower can get a much more accurate picture of nutrient levels within the system.
Root systems need not expand throughout the medium searching for nutrients as they will be evenly distributed throughout the liquid solution, and since the solution is constantly being aerated, to keep dissolved oxygen levels high, over-watering your plants becomes impossible.
The only thing that you must be aware of when growing through this method is the importance of avoiding the root’s exposure to any form of light. Since roots are highly sensitive, you must keep all light from penetrating the barrier between the canopy and root system.
Installation of a DWC (Deep Water Culture) System
Despite hydroponics reputation as an advanced system of growing, deep water culture is much closer to soil growing when it comes to complexity than other hydroponic techniques such as aeroponics. Though you’ll have to cope with the maintenance of the system, and managing nutrients is more involved than dumping some grow nutrients on top of your soil, the extra effort will pay off with the increase in quality and quantity of produced cannabis buds.
There are four crucial factors that you need to take into account when growing cannabis plants using deep water culture techniques. These include the following:
Growing Pots that will be Used
Since most of the root system will grow out of the bottom of the pot into the nutrient solution, pots will be small, they simply need to provide enough stability to hold the plant up. In most cases, growers use plastic net-pots to hold the plants. There are pots specifically fabricated for use in DWC systems. Inquire at any agricultural store or online retailer to get more details.
If you don’t have access to any of these pots, then you can making your own by drilling holes in plastic cups or pails as an alternative. Another method is to use a soldering iron or cutters and scissors to speed up this process; you want to fill the bottom of your growing container with holes so that the roots can exit out of the bottom to enter the nutrient solution.
After adding your plants, you’ll fill the rest of the container with clay pellets or any inert medium that has very low water retention. The medium will both stabilize the plant and prevent light from leaking into the lower chamber.
The Nutrient Solution
Normally, the water and nutrient solution are mixed together in equal amounts, but this can vary depending on how the plant reacts to the concentrations. For example, when starting new plants, you wan to slowly increase the nutrient levels over time to avoid shocking the plant. Draining and refilling the solution depends most on the E.C. (Electrical Conductivity) and pH values obtained by the instruments for checking levels. It is recommended to change the solution every week or two as needed.
It is important to be aware of the pH of the solution. Ideally, the nutrient solution should have an optimal pH of 5.8, Though, acceptable pH levels fall in the range of 5.2 to 6.2.
It is also important to manage the temperature of the solution. To get the best growth out of your plants, the temperature should be within the range 17-20 degrees Celsius. This range is not only healthier for the root system, but water at a lower temperature can absorb greater levels of oxygen. Temperature stability is also important, so if growing outdoors you should keep the water solution out of direct sunlight.
The reservoir is the container that holds your nutrient solution. It is possible to have the plants all grow above the main reservoir, but this is not recommended. It is better to have each plant above its own smaller bucket of solution, and pump the liquid between these buckets and the main reservoir.
Deep water culture works because you employ pumps and air-stones to constantly keep oxygen levels in your solution high. In other systems such as flood/drain and NFT, the root zone is constantly in motion and therefore gas exchange between the atmosphere and the water solution is high. Since deep water culture uses larger pools of water it is necessary to force oxygen into the solution. A pump with a minimum flow of one liter per hour is necessary and anywhere from one to fifteen liters per hour will work in an DWC system.
This brief introduction to deep water culture should give you the basics to evaluate whether this is a system that would work in your growing situation. Plenty of growers have had enormous success with this growing technique, and it is a great way to transition from the world of growing in soil to that of growing using hydroponics.