The water you use for your cannabis plants is an important consideration. Not all water is the same, so it’s important to hydrate your plants properly. If you talk with many aspiring cannabis cultivators, you’ll sometimes hear people ask if using tap water is okay. Using your tap water may be just fine, but it all depends on the water quality at your particular location. Read further to learn more about the water quality at your location and whether you need to adjust it.
There are several factors to growing healthy cannabis plants, and water is just one of them. Both hydroponic and soil grows rely on good water, so it’s imperative that both growing methods have a good water source. Proper pH is particularly important for hydroponics, less so for organic soil grows. Soil grows rely on top-quality soil and the right soil amendments (most cannabis growers and consumers prefer flower from organically grown plants), whether it’s from a bottle, compost, or a special recipe.
Likewise, proper pots with good drainage to eliminate excessive water are an important factor for every good grow. Lighting, air circulation, humidity, and temperature are important factors are well. Assuming all of those things are correct, a cannabis grow should thrive and produce a bountiful harvest. Let’s focus on the water factor to accomplish that goal.
First, let’s define the term. What exactly do we mean by “tap water”? The most basic definition means that it came out of a household tap, but what’s the source of the water? Is it hard city water (with chlorine and fluoride) or softer well water, with no harsh chemical and beneficial levels of minerals? There can be quite a bit of difference between the two.
Hard water refers to water that contains high level of calcium and magnesium compared to soft water, which has had these harsh impurities removed and contains sodium. Because city tap water often comes from reservoirs and water sources with high levels of contaminants, chlorine and fluoride are added as a safety measure. Soft water has no harsh impurities and contains very small levels of beneficial minerals or none at all, so it’s healthier for drinking, bathing—and cannabis.
Other categories of water include distilled water, which has all additives and minerals purged, and spring water, which contains no impurities but all of the beneficial minerals. Spring water ranks among one of the best waters for drinking, and also is good for growing cannabis, although it’s rather expensive.
Testing Tap Water pH: An Important Evaluation
Most tap water is city water—with all of the additives city water is known for—so this is the water all growers should monitor and test to determine if treatment is necessary for optimum growth rates and plant vigor. Regardless of the source, correct water pH is very important. Testing water pH should be a standard procedure for every cannabis grower.
Water pH test kits are readily available and easy to use. Cannabis does best with a pH reading between 6-7. A level of 6.5 is perfect—even lower for hydroponic grows. For hydroponic cultivation, a level between 5-6 is best, with 5.5 being ideal. Most likely, your water won’t be right on target. While you can likely grow cannabis with it, your plants won’t grow with the same vigor that they will with pH in the proper range. Most likely, you will need to decrease your taps water’s pH rather than increase it. Using a reliable pH test, collect some tap water and take a reading. High pH means the water is too alkaline, and low pH means the water is too acidic. Neither extreme is desirable. You want to be somewhere in the middle. Water transports vital nutrients throughout a cannabis plant’s structure to help it grow. Improper pH prevents water from delivering these important building blocks.
If your water pH is outside of the desirable range, don’t despair. There are easily obtainable products that will adjust it to a good level. Cannabis growers should have some standard items in their cultivation arsenal that go beyond the most obvious ones. A pH booster and a pH reducer should be at your disposal in the event that you need them. These products should be easy to locate at your local nursery or grow center. Test your tap water and follow the directions on your booster or reducer to adjust your pH to the optimum level. Most likely, the pH reducer will be the product most often used, since a lot of water straight from the tap tends to run a little high in pH.
Are pH Boosters and Reducers Really Necessary?
Depending on the methods you use for growing cannabis, there may not be a compelling need to boost or reduce your tap water’s pH. If you’re growing organically in soil, you may not need to adjust your pH at all. Often, organic fertilizers and soil amendments that you mix in the water will automatically adjust the pH. The creators of these products anticipate that the water pH used by the majority of their customers is usually a bit high, so they create soil amendments that address the need to adjust tap water pH.
For example, say your tap water has a pH of 8.5. By following the soil amendment directions and providing the plants with the correct amount, water pH may reduce to the perfect 6.5 level. To ensure that this is the case, additional testing will reveal if the tap water is at the appropriate pH level. Make sure you test the water after mixing in the soil amendments.
Dechlorinating Your Tap Water
Many cannabis growers who use city tap water worry about the chlorine content. Cannabis can usually grow fairly well with chlorinated water. For instance, just think about all of the beautiful lawns and lush gardens that grow just fine with city water straight from a garden hose.
Despite this, many cannabis cultivators like to remove all unnecessary and undesirable elements from this water. To do this with tap water is easy but requires some planning and steps that are fairly simple, especially for smaller grows. Fill a large container (a large bucket serves as a good example) with tap water and set it aside for 24 hours. A full day is all that’s necessary for the chlorine in the water to evaporate, leaving the water more suitable for cultivation. Dechlorinating water doesn’t require any expensive products or elaborate procedures.
Special filters will also eliminate chlorine and adjust hard water to an appropriate softness for cannabis plants. Activated carbon filters and chemical products will remove chlorine quickly and is more convenient for large grows. Investing in a high-quality reverse osmosis system is an ideal way to have a steady supply of perfect cannabis water available to you at all times.
Perfect Water Results in Perfect Plants
Adjusting your water to make it as perfect as possible for your grow is a sound cultivation best practice. While you can certainly grow cannabis with mediocre water, it won’t thrive like it will with water at the correct softness, the proper pH, and free from chlorine.
Adjusting your tap water with the appropriate equipment and/or additives will result in lusher plants, better yield, and bigger flowers with excellent terpenes. When it comes time to harvest, you’ll be glad you took the extra step to ensure your grow is as successful as possible.