According to Cannabis Training University, two key resources are essential to any successful cannabis grow, regardless of whether its private or commercial: water and light:
Full-spectrum lighting can come from either the sun or indoor grow lights, but the water for your grow will most likely come from your city water on tap. Diverting water from natural creeks and streams is not possible for most people, and when it is, it’s usually illegal. That means it’s critical to eliminate water waste whenever possible.
The bills for water and electricity can run very high, so cost-cutting measures are good to research and put in place to increase your bottom line. Because drought is a reality in many legal cannabis states during recent years—particularly those in the west—water bills commonly reach hundreds or several thousands of dollars to keep a good cannabis grow up and running. Both California and Colorado are two of the big regions feeling the crunch from water shortages. California, as well as being a huge state with a large population and a prime cannabis growing climate, also has a need for massive amounts of water for the cultivation of other crops. California’s Salinas Valley is commonly called “the salad bowl of the world” because 70 percent of the United States’ lettuce crop is grown there—as well as other produce like strawberries, broccoli, and peppers.
California’s San Juaquin Valley (aka Central Valley) Is another region with a huge amount of crop cultivation. Many of the country’s tomatoes, grapes, sugar beets, walnuts, almonds, hay, cotton, and many other crops are grown there. In order to feed the nation with these crops, an ongoing water supply is a necessity.
Drought and water shortages in Colorado are largely due to the fact that the Colorado River provides water for all of Southern California’s agriculture needs (citrus fruit, avocados, and other crops), as well as drinking water for that large and highly populated area. The Colorado River also supplies water to six other states and Mexico. This being the case, it’s easy to see why Colorado’s water can be in short supply.
Cannabis Cultivation’s Impact on Water Supply
Western states have climates that allow both indoor and outdoor cultivation of cannabis, although some are more limited in this regard than others. Northern California is well known for its optimum climate for cannabis, with the “Emerald Triangle” of Humboldt, Trinity, and Mendocino Counties all known for abundant production that in year’s past supplied much of the country’s marijuana. Indeed, the name “Humboldt” is practically synonymous with high-quality cannabis. As legal marijuana growing has proliferated even more in the region during recent years due to the now-legal status of the plant, the use of water and the diversion of it from rivers and streams has taken a big toll on this already-limited resource.
The need to limit water use for marijuana production is an undeniable fact. Because hydroponic growing is a water-based cultivation method, some people erroneously assume that it requires more water. This is far from the case, and hydroponic crops require as much as ten times less water than soil grows. The constant need to water soil, particularly outdoors, eventually adds up to a much greater volume of water than the constant water source necessary for hydroponics. If water usage is a huge concern for your grow, consider growing hydroponically. Rather than enter into a debate about whether soil or hydroponic grows are superior, some facts can’t be denied. Hydroponics not only uses water more efficiently, but under optimum conditions, growth rate is faster and yield is higher.
Water Conservation Measures
There are a number of steps you can take to make the best use of your water. Sometimes some simple changes can significantly alter efficient water usage and minimize waste. More efficient use of water will lower your operating costs. If you grow cannabis commercially, efficient use of water also will increase your return on investment (ROI).
Let’s examine some of the ways to maximize water usage:
Measure PPM and pH
To make sure you’re making the best use of your water, the most important first step is to check your water quality. A parts-per-million (PPM) test using a typical water pH meter will determine of your PPM and pH are at optimum levels. If PPM is running high, nutrient lockout is occurring with your grow, which ultimately will waste valuable water.
Indoor grows make more efficient use of water
While growing cannabis outdoors has definite advantages, one of them is not efficient water use. Much more water evaporation and runoff will inevitably occur outdoors compared to indoors. If your high-water bill makes water conservation a main concern, strong consider the controlled environment of an indoor grows. Greenhouse grows are another option and capture some of the best of outdoor and indoor growing.
Use a pH booster or reducer
Invest in better water filtration, or use a liquid nutrient that automatically adjusts your water pH and PPM to proper levels. If PPM runs too high in your water, much of it will run down the drain rather than feed your plants.
Observe runoff amounts
A wise course of action when watering potted cannabis plants is to observe the amount of water exiting the pots. Approximately 15-20 percent of water runoff is acceptable, but more is an indication that your water usage could be more efficient. Make adjustments as necessary.
Reclaim as much water as possible
An indoor grow allows for easier collection of run-off and condensation than is possible outdoors. When conserving water, every little bit helps, so reclaimed water with filtration, if necessary, to minimize water use.
For soil grows either indoors or outdoors, a drip irrigation system will provide a more exact way of watering and feeding your plants. Providing plants with water by flushing them with a large and sudden amount will inevitably result in runoff and inefficient water use. Drip irrigation, when done properly at the correct rate, is an outstanding way to conserve water. Many crops, not just cannabis, thrive when grown with a good drip irrigation system.
If your area of the country has a monsoon season—or merely a predictable amount of rainfall—by all means collect the water. Large tubs located at the site of rain gutter runoff or other water-collection sites can be put to use for either an indoor or outdoor grow. Rainwater lacks any of the fluoride, chlorine, and any other additives that typically are found in city water. Your plants will appreciate its purity.
Select your growing medium wisely. When it comes to water absorption and retention, not all grow media are created equally. Preparing a good soil mixture using the right ingredients will help conserve water. Organic soil ingredients like peat moss, coco coir, compost, and other substances like perlite and vermiculite will not only retain water well but provide an excellent environment for cannabis to grow.
Author: Heather Allman