Jul 11, 2016
Categories : Cannabis cultivation
Any experienced grower can tell you that managing the right pH levels for your cannabis plants can be the difference between success and failure. Cannabis plants like all plants and even all life forms require a specific pH level to thrive, ensuring they uptake the correct nutrients for successful growth. When it comes to pH levels a 1.0 difference in the scale is equivalent to a tenfold increase in concentration! So it's easy to see how even a small drop or increase in pH levels can have significant consequences for your beloved weed. The good news is that you don't need a Ph.D. to know your pH levels, just the right equipment, and some good old-fashioned know-how.
What is pH and How Does It Affect Cannabis?
Simply put pH is the measure of how acidic or alkaline a substance is. The middle point 7.0 is neutral with anything lower acidic and anything higher alkaline. Remember the 1.0 point difference we spoke about earlier, now you can see how easy it would be to slip and remember that that 1.0 difference could be a tenfold increase in acidity if it became 6.0. So where does cannabis fit into all of this? Typically, the optimum pH for marijuana plants is between 6.0-6.8, now this can vary depending on the type of grow you have. Hydroponic and soil environments have different preferences when it comes to pH levels essentially because the soil acts as a buffer allowing a slower uptake and slightly easier control of pH levels. Poorly controlled pH levels can lead to a variety of symptoms, too acidic and this can lead to burnt root tips and black spots whilst too alkaline can lead to chlorotic leaves and yellowing of veins.
Providing the ideal pH level for cannabis to grow will ensure the maximum uptake of nutrients from the medium you are growing in. So if you want the best possible weed from your grow, regardless of the environment maintaining that sweet spot of 6.0-6.8 is vital. Fortunately for us, there are a number of ways to monitor pH levels and subsequently, adjust. It is important to remember that if your pH levels do move out of the required range it CAN be adjusted and rectified. This is why frequent monitoring is a key part of a successful grow.
What will I need to Monitor and Adjust pH Levels?
Let's start with the actual measurement of pH levels. Before you start mixing chemical compounds in a lab coat and goggles you need to know if it is actually needed. Fortunately, there is a lot of choices when it comes to monitoring your pH levels so despite your budget there will be a solution for you. This can range from tester strips, which turn a respective colour dependent on the pH of the substance you are testing to digital pH meters. The latter is often preferred as it offers a more accurate and precise calculation of the pH levels. In the long run, any kind of digital pH reader will work out more cost effective versus buying copious amounts of strips so it's always worth playing the long game, especially as they can be used in future grows!
So we have an ideal pH range for cannabis and we have a means of testing it, but how do we actually adjust the pH of our grow environment? With pH up and pH down of course, whilst not the most imaginative product branding it does exactly what it says. It is worth noting that adding these solutions to your grow environment takes some patients. Adding too much pH down to then try and counteract with the relevant pH up will cause unnecessary stress on your weed. Make sure to add small amount allowing it be fully absorbed before testing, this will ensure you pH readings are accurate and a smaller dip or rise is far easier to counteract. Mixing up the pH adjuster in a separate jug or container is usually the best way to achieve this.
Choosing your Grow Medium
Depending on which medium you choose to grow will vary the optimum pH levels for you cannabis plants. Soils based grows are typically easier to control when it comes to pH, ultimately because any changes in pH level will firstly be absorbed into the soil, meaning you can catch any fluctuations before they have too much of an impact on your plants. Remember we mentioned hydroponic environments needed a different pH level? Because there is no soil buffer, the nutrients are absorbed directly from the water and as a result are absorbed both quicker and usually more efficiently than a soil based grow. For this reason, it is advised to keep the pH level slightly more acidic, somewhere between 5.5-6.5. You will notice though that we are still in that just under neutral sweet spot.
The tools for monitoring and adjusting your pH levels remain the same regardless of environment. As long as you ensure frequent monitoring and adding small amounts of pH adjuster at any one time, whether it is your first grow or hundredth grow pH levels shouldn't give you too much trouble.