Deep Water Culture (DWC) For Huge Cannabis Yield

Deep Water Culture (DWC) For Huge Cannabis Yield
December 03, 2019

Apart from delivering the utmost satisfaction to recreational users, cannabis also has numerous medical benefits. And, over the last several decades, seed banks and enthusiasts have bred varieties to suit different purposes. Although some have opted to keep their creations proprietary, many others have made seeds available. As such, not only could one buy the flowers from dispensaries, choice strains could also grow in the comfort of the house.

Home growers can choose from two types of growing mediums. While soil is the most common, more people are now adapting hydroponicsfor its inherent benefits. It may require an initial investment but could save on costs over the long-term. Not only that, cannabis plants can achieve a faster growth rate and produce more flowers.

Hydroponics And Deep Water Culture

Hydroponics growing systems offer cannabis cultivators absolute control. It also significantly reduces factors that may be detrimental to the health of the plants. For example, using soil could come at the expense of exposure to harmful chemicals and microorganisms. Soil-less gardening, on the other hand, provides a cleaner and safer environment that is conducive to optimal growth.

Granted that there are a few strains which thrive better using soil as a medium, most plants are adaptable to hydroponics. For cannabis growers, there are six main types:

  1. Deep Water Culture System
  2. Drip System
  3. Ebb and Flow System
  4. Nutrient Film Technique (NFT)
  5. Wick System
  6. Aeroponic System

Of these six, the most common is Deep Water Culture (DWC). Its ease of setting up and operation, in fact, makes is an attractive choice for beginners in cultivating cannabis. And, it is likely the most economical too.

Cannabis On A Hydroponics Setup
Hydroponics Setup

Key Benefits Of DWC

In this system, plants are placed in pots or net cups and suspended above a reservoir. The roots, meanwhile, are completely submerged in the aerated nutrient-rich water solution.

Roots And Nutrients

In soil, tap roots stretch and could reach several feet deep in search of moisture and nutrients. That is not the case with deep water culture as the root system already has a consistent supply of nutrients. Although it continues to grow, it does not have to spend too much energy as it would if grown in soil. As a result, it could focus more on flowering and production of THC.

Aeration And Oxygen

As the root system of plants continues to grow, it could lead to root binding due to the somewhat restricted space of the reservoir. It could potentially lead to suffocation as access to oxygen becomes restricted. For this reason, an airstone placed at the bottom pumps air into the tank to ensure that there is more than enough oxygen to help in the respiration process far beyond what is possible if using soil.

Sterile Environment

The amount of water used in hydroponics is up to 20 times lower than growing in soil. For home growers, that may not matter much. What does matter, though, is that using DWC growing system already eliminates soil-borne pests and diseases.

Home Deep Water Culture System For Growing Cannabis

Deep Water Culture System
Deep Water Culture System

There are three things to think about when setting up a deep water culture system – water, oxygen, and nutrients. As for the materials needed, some could already be available in the house.

1. Water Reservoir

A black-colored thick plastic container or bucket is suitable. Also, it should hold at least have a 5-gallon capacity to ensure there is more than enough room for the roots to grow without leading to root binding. The choice of color is not for aesthetic reasons. Instead, it is to prevent the penetration of light and allow the growth of green algae. Not only does it suffocate the root system, but it also competes for water and nutrients as well as clog up tubings.

2. Net Pots

These are pots with holes that are for use with hydroponics systems and readily available in most garden supply stores. If not in a nearby shop, there is a whole bunch of online retailers where one could purchase some.

Some growers, though, could adhere to the concept of DIY and make these pots from almost anything at home. For example, one could use 200 mL plastic cups and melt holes using a soldering iron. The most important thing to remember is to make sure that the edges of the holes are smooth. Sharp edges could injure the root system and hinder the growth of plants.

To hold the plants in place, growers have a choice of using hydroton clay pellets, lava rocks, or perlite.

3. Air pump And Airstones

A deep water culture growing system needs a pump to aerate the tank. Without it, plants cannot grow. These pumps are not expensive and are available in pet and hydroponics gardening supply stores.

For the air pump, choose one that is of good quality. As a general rule, pick one with an air flow volume that is twice the capacity of the water reservoir. If stealth is a priority, there are also pumps that generate low noise levels.

As for airstones, there are different types to choose from, and these are:

  • Ceramic Disc Airstone. This flat round disc, made of durable material, provides more bubbles that are fine and distributed in a wide area. It is also suitable for pumps that have an air flow rate of 2.5 to 10 liters per minute.
  • Cylinder Airstone.  Also called the “coke can airstone,” its elongated cylindrical shape allows it to distributes bubbles in a wide area. It is also the best option for large reservoirs and pumps that delivers 5 to 10 liters per minute.
  • Golf Ball Airstone. It is the most common one used for deep water culture hydroponics system. Resembling its namesake, it typically comes in 25mm diameter and is suitable for pumps that have an air flow of 1.5 to 5 liters per minute.

Because plants in deep water culture can suffocate without aeration, it is best to have at least one back up air pump. Also, while it is possible to clean clogged airstones, growers are not likely to savage all. As such, having extra airstones is also recommended.

4. Meters And Nutrient Solution

The heart and soul of deep water culture or any hydroponics system is the nutrient solution. It is, therefore, incumbent upon growers not only to make sure it is adequate minerals and other essentials but also to have enough oxygen and pH balance.


As it increases, the potential for dissolved oxygen decreases. Not only that, but it also lets anaerobic pathogens to thrive and cause root rot. For this reason, growers would want to keep the temperature of the nutrient solution low. It should also not be too cold as it hinders the growth of cannabis plants. Typically, the ideal temperature is in the range of 18 to 22°C.

Most home growers should not experience any problem controlling the temperature of the nutrient solution. However, there are instances when it can be troublesome. For example, planting outdoors using the deep water culture system.

As a means to adjust the temperature to its optimal range, growers can use an automated water chiller if it is too warm. As an option, one could also opt to use frozen water filled in a 2-liter plastic bottle. And, if the temperature is too low, a submersible titanium heater with thermostat works wonders.

Having a chiller or heater are fixes. DWC cannabis growers do need to have a thermometer to measure and monitor the temperature. These meters are widely available, and many come with other functions that are essential to maintaining a healthy nutrient solution environment.


There are leading factors in the ability of the nutrient solution to hold dissolved oxygen.

Bubbles released using an air pump and airstones causes a tension on the surface of the solution. And, that is how it helps keep the oxygen level more than adequate. At the same time, keeping the temperature in the optimal range helps maintain that level.

pH Balance

The potential hydrogen (pH) determines the solubility of nutrients. It is also in this area where many home growers might encounter some problems.

In deep water culture, and other hydroponics growing systems, the ideal range should be 5.5 to 5.8 pH. After establishing the proper temperature and turning on the air pump, it is unlikely that growers would have a problem moving forward. The pH level, on the other hand, fluctuates most especially after changing water or adding nutrients and additives. Hence, it requires constant monitoring.

Adjusting pH values might be cumbersome for some growers as it could take hours to stabilize. In many cases, the problem arises because growers think they already set it correctly after adding nutrients without realizing later that it changed. Like thermometers, many pH meters in the market not only allows for monitoring but could also sound an alarm if there is a severe deviation from the optimal range.

Nutrient Solution

Instead of the cannabis plants growing roots at a higher rate and search for nutrients, DWC lets growers supply nutrients directly. Using a TDS/EC meter comes in handy for this purpose. The total dissolved solids affect the electrical conductivity of the solution. Hence, it can indicate if there is a need for adding nutrients. Cannabis seedlings typically begin with 300 ppm, and as it progresses to the vegetative stage, growers raise it to 1000 ppm. Some specific strains, though, could require as much as 2400 ppm.

Advantages And Disadvantages Of Growing Cannabis Using DWC

Like any method of growing cannabis or any plant for that matter, there are benefits as well as the problems it may present. In other words, there is no such thing as a perfect system.


The constant supply of nutrients and oxygen in the solution results in accelerated growth. Compared to growing in soil, growers end up using fewer nutrients and water.

Aeration improves the ability of the root system to not only absorb nutrients but also helps increase the growth rate of cells.

Easy to set up, and cheap too.


Growers need to have a backup air pump and extra air stones. Of utmost importance is electricity to keep the pump running. Aside from the pump possibly failing, a loss of power for a prolonged period can cause the plants to suffocate and drown.

DWC Let Beginners Get Huge Cannabis Yields

As alluded to earlier, there are different methods of hydroponics. None, though, is as close to DWC with regards to ease of setting up and its operation. Unless one runs into a catastrophic problem, it works as well as any system by not only accelerating the growth of cannabis but also improving its potency and yield.

Even its one critical disadvantage of the pump stopping in case of a power outage or breakage, it is also the same concern shared by any form of indoor gardening. The grow light system, for instance, is the first thing that comes to mind.

Overall, it is hard to argue against the cheap cost of setting one up and getting started with soil-less cannabis cultivation. While a basic system does not allow for the simultaneous cultivation of different strains or plants in varying growth stages, it is an excellent way for beginners to finally experience the joy of home cultivation without so much of an effort in going through the technical details and complexities of other systems.

High THC Cannabis

Yes, there are many things to consider. But in the end, one thing that should stand out from all the pros and cons of using DWC is this. It has the potential to let even newbies and beginners in growing cannabis harvest a huge yield of potent flowers.