Deep Water Culture (DWC) is a method of hydroponic growing that I argue is easier than growing in soil. You don’t have to worry about watering schedules as your roots sit in the nutrient solution 24/7. This gives the plants a buffer where they can uptake as much water or nutrients as they require. And gives lazy people, like you and I, the ability to leave the plants unattended for days, even weeks at a time.
This website has all the information you will need to set up a run a successful DWC grow. Even if you have never grown in soil before I encourage you to start with DWC.
Thanks to advancements in LED light technology DWC can be run without any air conditioning or water chillers, as was often necessary with HPS lights. DWC maximizes yields/minimizes veg time when working under the confines of 4 or 6 plant maximums that most recreational growers face.
DWC is more simple to set up than traditional “flood and drain” hydroponics which requires piping and submersible water pumps that run on a timer (multiple points of failure).
Recirculating DWC (rDWC) – is a method of growing that uses pipes to combine multiple containers into a single system. Water is recirculated between the containers using pumps to create flow. The primary disadvantage of rDWC is that root rot, or other pathogens, can quickly spread through the system. Traditional DWC has a modular approach and less moving parts, so this website primarily discusses DWC.
There are two school of thought when it comes to DWC:
Sterile DWC – involves sanitation of water reservoir, hydroton. Water temperatures are kept below 68F, light leaks are mitigated and dissolved oxygen is maximized with large air stones and strong pumps creating an environment where bacteria cannot thrive. This is my preferred method, and the one I recommend most people try first
Beneficial Bacteria DWC– involves adding products like Hydroguard to your DWC nutrient solution. The idea is that these healthy bacteria will outcompete the pathogens that cause root rot.
The most economical way to run beneficial bacteria in DWC is to brew a beneficial microbe tea. I usually inoculate my plants once or twice during the vegetative stage and never have any issues with root rot.
Water temperatures must be kept below 72F and ideally below 70F in a DWC application. Any higher and you risk root rot. Some common methods for keeping water temps down include:
- Paint the container white
- Increase ventilation
- Use a thermocontroller to run exhaust fan
- Keep air pump outside the grow area so you are not pumping warm air through the container
- Use large totes instead of bucket for reservoir. More water = higher thermal capacity and less fluctuations in temperature
- Add insulation to reservoir
- If you are dealing with extreme heat I have seen redditors in California use 5 gallon coolers for their DWC reservoir
- A not so cheap option is to add a water chiller to your system. I would save this as a last resort
If you can keep your ambient air temperatures below 78-80F during lights on you should be able to keep your water temps in the low 70s and should be fine for DWC. If you cannot keep your ambient temps below 80F you may want to consider sub irrigated planters.
Sub Irrigated Planters (SIPs) provide many of the advantages of DWC (e.g. not having to water frequently, no nutrient waste) without the risk of root rot in high temperature applications.
SIPs can be run both indoor and outdoor and are my preferred method for growing outdoors.
