If you plan on growing cannabis at home, one of the most essential factors you need to keep in mind is the pH level. The pH level, or in other words, the acidity level of your growing medium and watering solutions is important to keep in mind at all times in fact, if the PH level is off, whether it be in either direction, then you will have a serious problem on your hands.
Although many people always consider other factors such as lighting, watering, nutrients, and more, many people forget about the pH level. For the record, the pH level in your cannabis grow medium is also directly related to how well cannabis plants can uptake nutrients. If the pH level isn’t right, then your cannabis plant won’t be able to eat properly, which means that it won’t grow big and healthy.
Improper pH levels can lead to nutrient lockout, which in turn leads to cannabis plants not getting the fuel they need to grow buds that are potent and flavorful. Therefore, understanding and adjusting cannabis plant PH levels for optimal growth is one of the first pieces of knowledge you should take in before you start your cannabis growing journey.
The pH Scale – What is pH Level?
In simplest terms, pH is a quantitative measure of the acidity or basicity of a specific liquid, which in this case may also apply to the growing medium that you use for cannabis. In other words, the pH is a definition of exactly how acidic or basic a specific liquid is, such as your nutrient growing solution.
Furthermore, the pH scale ranges from 1 to 14, with 1 being extremely acidic, such as battery acid, and 14 being extremely basic. A neutral pH level is 7.0, which means that a solution is neither basic nor acidic. As you might be able to tell, as far as plant life is concerned, somewhere fairly close to the middle is generally considered best.
Why Are pH Levels Important for Cannabis Growth?
Some people might think that the acidity of the soil is not very important, but this couldn’t be any further from the truth. In fact, having the right pH level is extremely important for cannabis plants, and this is true for a variety of reasons.
Nutrient Absorption
First and foremost, cannabis plants need a specific pH range so they can absorb nutrients in an optimal manner. If the pH level is either too high or too low, both nutrient toxicities and nutrient deficiencies can occur. It’s all about providing your cannabis plants with ideal access to nutrients.
On that note, there are very many different nutrients that your cannabis plants need, and many of them have different ranges at which they are best absorbed at. For instance, magnesium and calcium are more readily available at slightly higher pH levels, whereas lower pH levels benefit other specific nutrients, such as iron.
When it comes down to it, if the pH level goes too far in either direction, what is known as nutrient lockout, which means that your plant is not able to absorb nutrients. Even if those nutrients are technically present in the growing medium, if a plant is suffering from nutrient lockout, it won’t be able to absorb any of them.
Beneficial Microbes
What you then also need to consider is microbial activity. There are many different microbes present in soil that can help with root health, nutrient cycling, and more. Without these beneficial microbes, your plants won’t be nearly as healthy as they would otherwise be. Maintaining a correct pH range is essential for maintaining a healthy microbial community.
Enzymatic Function
This is also related to enzyme function. There are plenty of enzymatic processes present in the plant, as well as in the soil, such as respiration and photosynthesis.
Many of these processes are pH dependent, which means that if your cannabis plant is not kept in the proper pH range, it won’t be able to respirate or perform photosynthesis properly.
There is also the simple fact that if you don’t keep your cannabis plants within the proper pH range, it can also induce what is known as pH stress, which ultimately makes them more susceptible to diseases and stress.
What is the Optimal pH Level for Cannabis Growth?
Now that you know why maintaining the correct pH level is so important for your cannabis plants, let’s take a closer look at what the ideal pH level is.
Cannabis Soil pH
If you are growing your cannabis plants in soil, or in other words, in a soil growing medium, then the pH level should be anywhere between 6.0 and 6.8. The ideal target pH level for cannabis plants being grown in soil is somewhere around 6.5.
The simple fact here is that if you grow your cannabis plants in soil, they usually prefer it to be slightly more acidic than if you grow hydroponically. If you maintain this range, your cannabis plants should be able to easily absorb nutrients and maintain a healthy structure.
Hydroponics pH
If it is a hydroponic growing system that we are talking about, then the pH level should be kept slightly lower. Generally speaking, no matter the type of hydroponic system you are using, the pH level should be between 5.5 and 6.5, with somewhere around 5.8 being ideal.
Remember however that growing hydroponically is very difficult because you need to precisely control the nutrients and pH levels in the water. Water is much more susceptible to rapid fluctuations than soil, so this is something you need to remember.
Coco Coir
If you happen to be growing in Coco Coir, this is usually considered more of a hydroponic system than it is a soil growing medium, which means that the ideal pH level here is also around 5.8.
How To Adjust the pH Level When Growing Weed
Now that you know what the ideal pH level is supposed to be for your cannabis grow operation, let’s take a closer look at how you can either lower or raise the pH levels for cannabis, depending on what your needs are.
How to Lower the pH Level for Cannabis
First, let’s take a quick look at how to lower pH levels for cannabis growing. Now, one of the easiest solutions here is to get a solution known as pH down.
This is a very common solution used to lower the pH levels for many different types of plant growing, whether cannabis or otherwise. They usually contain either citric acid or phosphoric acid. Make sure to very closely follow the instructions as listed on the label, because too much of this product can have disastrous consequences.
If you’re looking for a much easier and more cost-effective solution, something you can try doing is using vinegar. Vinegar is acidic and it will lower the pH level of your nutrient solution. Start with just a teaspoon per gallon and then increase the amount of vinegar as needed. Be sure to keep monitoring the pH level of nutrient solution as you add vinegar.
On that note, there are also other substances you can use, including citric acid, lemon juice, phosphoric acid, and even some sulfur-based products. However, make sure that you only make very small adjustments, because even a little bit any of these substances can have drastic impacts on the pH levels of your watering solutions. Remember, a little bit goes a long way.
How to Raise the pH Level for Cannabis
If the pH level of your nutrient solution or growing medium is too low, there are some good ways to raise it.
One of the easiest ways to raise the pH level for cannabis is to use something known as pH up, a chemical solution that you can purchase in most gardening stores. These are usually based these usually contain either sodium hydroxide or potassium hydroxide, as both are very basic in nature.
Just like with the pH down solution, make sure to follow the instructions on the label very carefully, because even a little bit PH up can make a big difference in terms of the pH level.
However, if you don’t want to use a chemical solution such as this, and you’d rather be a bit more cost effective, there are other substances you can use to increase the pH level for growing cannabis. Just some of the substances you can use on this front include baking soda, potassium carbonate, limestone, dolomite lime, or shell flower.
Just like with the above substances used to lower the pH level, with these substances that are designed to raise the pH level, try to only use very small amounts at once and continuously monitor the changes. You don’t want to add too much of any one of these substances to your nutrient solution, only to figure out the pH is now off in the other direction.
Always Test pH Levels
Some people might be intimidated by all of this talk about pH levels and acidity, whereas the reality is that keeping track is very simple. All you need is a pH meter. A pH meter is a simple device that has electrodes at the front that you place into a watering solution, and it then provides you with all of the information you need.
A PH meter is a battery operated device that is extremely user friendly and only cost a few dollars. For the record, if you get a digital PH meter, it will tell you the exact PH level that your current watering solution is that.
Therefore, every time you use any kind of pH adjusters to adjust the pH values of your nutrient solution, make sure to keep measuring and paying attention to the pH reading. Once again, a little bit of any solution designed for adjusting pH levels can make a big difference, so you want to continuously monitor as you are making changes.
What Happens to Cannabis Plants if the pH Level is Too High?
If the pH level for your cannabis plant is too high, the result will be what is known as nutrient lockout, which is when cannabis plants can no longer properly absorb nutrients. Both the macronutrients and micronutrients that cannabis plants need to survive will not be readily available anymore if pH levels are too high.
Furthermore, if pH levels are too high, you may also notice what is known as leaf yellowing or chlorosis, combined with slow growth, reduced yields, and an increased susceptibility to diseases and pests. Furthermore, if pH levels are consistently too high, it can also affect both the cannabinoid and terpene profiles, ultimately resulting in less flavorful and less potent buds.
What Happens if the pH Level is Too Low?
In many cases, if the pH level is too low for your cannabis plants, it can lead to excessive nutrient availability, or in some cases nutrient lockout. What is interesting to note is that low pH levels in some cases can lead to cannabis plants absorbing excessive nutrients, whereas in others it may lead to the cannabis plants not being able to absorb nutrients. It really depends on the exact nutrient in question.
Something else worth noting is that low pH levels can also lead to microbial imbalances. There are plenty of microorganisms present in soil, such as fungi and bacteria, which are beneficial for the growth of your cannabis plants. However, if PH levels are too low, many of these bacteria and fungi will not be able to survive, therefore negatively affecting the overall health of your plant. Overall, both high and low PH levels can have devastating effects on your cannabis plants.
What Affects the pH Level When Growing Cannabis?
Before we call it a day, let’s just note that not everyone will have the exact same issues when it comes to adjusting pH levels for their cannabis plants.
The simple reality is that the growing stage that your cannabis plant is in, the nutrient solutions you are using, the water source, and the growing medium, as well as soil pH buffering and runoff, can all have their impacts on pH levels.
Therefore, it is essential that if you plan on growing cannabis at home, that you continuously test for pH levels to account for your specific situation.
Conclusion
Growing healthy cannabis plants is all about knowing what the ideal pH for cannabis is. Remember, it’s all about maintaining the optimal pH range, and if you have to, using pH adjusters to increase or decrease pH values as needed. Remember, healthy cannabis plants need to be able to absorb nutrients, which really comes down to cannabis pH and the optimal range.
If you plan on being able to monitor the pH level as effectively as possible, using digital pH meters is recommended. Measuring pH levels using something like a pH meter is really the only way to figure out whether or not you have pH imbalances. Understanding soil pH is essential to the success of your cannabis growing project.
