What’s the Ideal Water Temperature for Cannabis Plants?
Many people think water is, well, just water. As someone focused on plant growth, you know there is more to it than this. Not all water is the same, and this is an important factor on the growth of your cannabis plants. Your water can be the difference between success and failure.
Cannabis plants, along with a lot of other plants, contain 80% water. They need water as they grow for photosynthesis, cooling, and to transport nutrients and dissolved nutrients into the plant.
If you want your plants to grow, and you do, you should be paying special attention to the water temps in your grow space. What is the right water temperature? Why does it matter? Let’s answer all of these questions and more, right now.
Table of Contents
What to Consider When Watering Cannabis
If you’re using a hydroponic system, you must pay close attention to the water going to your plants. It probably goes without saying, but the water you use must be as clean as possible. Good drinking water doesn’t always make good water for nurturing a cannabis plant. This is why tap water needs to be tested before it is used on plants.
Consider purchasing an EC meter as well as a pH meter. With the EC meter, we can determine whether or not the concentration of nutrients in the water is best to provide optimum plant growth. A pH meter determines the acidity of water. You want to ensure the pH of the water being used is approximately 5.5-6.5. With the concentration of nutrients and the pH at the right levels, your cannabis plants will have what they need to be absorbing nutrients and growing. You can read more about proper pH for cannabis here.
Don’t Forget About PPM.
PPM means parts per million. It measures the number of minerals in your water, or the total dissolved solids. PPM levels vary depending on where you live. You may have higher or lower than the ideal amount as water from wells in rural areas usually have natural minerals but city water has chemicals added to treat it.
You want to measure and adjust your water to achieve a good PPM and help your cannabis crop to avoid toxicities or nutrient deficiencies. The best way to control the PPM range for cannabis is through a reverse osmosis system where water has 0 to 10 PPM.
Best Water Temperature for Cannabis Plants
Cooler water that is high in oxygen is best for growing cannabis. Experts at watering plants tell us that the best water temp for cannabis plants ranges between 68 and 73℉. Water that is too warm, meaning above 73℉, is then low in oxygen. The amount of oxygen is very important! This being off can lead to an anaerobic environment in the root zone, leading to diseases like pythium (root disease). Water that’s too low, below 55℉, can shock your plant. Hydrating your crops with colder water will lower metabolic capacity, and reduce the overall growth and yield.
Achieving the Right Water Temperature
If you’re using a grow room and not growing your crop outdoors, it’s much easier to control the water your plants are getting. Keeping water temperature for cannabis cool can be tricky because an ideal grow room has air temperature between 75 and 88℉. To keep the water temperature lower than this, you can add cold hot water to adjust it, use cooling equipment, or move the basins to a cool area away from the heat-producing lights and electrical equipment.
The water temperature and quality for cannabis plants is incredibly important, and not something to leave to chance. It’s simple to get the best water for growing cannabis in a hydroponic nutrient solution – if you have help, that is. From grow lights, to water quality, to temperature range, there’s a lot to think about. We’re here to help you with it all!