A gradual increase, as well as a slow decline, in EC will allow you to determine how far you are able to push your plants while avoiding possible shock caused by drastic swings in nutrient concentration.
Whether you are growing with a soil or soilless setup, pH (potential hydrogen) measures the acidity and alkalinity of the medium, which in turn controls the nutrients the plant can absorb.
The pH and nutrient concentration of a cannabis plant’s medium is a lot like a transistor radio; you have to dial in the right numbers to unlock its full potential.
Unlike pH, nutrient concentration should be adjusted for different strains of cannabis. The electroconductivity (EC) or total dissolved solids (TDS) are both measurements used to determine the nutrient concentration in your medium.
Allowing a pH range, regardless of the medium, ensures the plant is able to absorb the variety of nutrients required for optimum growth. For example, the plant's ability to absorb manganese increases with a more acidic medium. Numerous pH and nutrient uptake charts are available online to illustrate the ideal pH for each element needed throughout the vegetative and flowering stages of growth.
Whether or not different cannabis strains thrive under distinctive pH levels is an area that has undergone little scientific scrutiny. Hach é doubts that exploring specific acidity levels based on cannabis species would produce noticeable improvements in yield or quality.
Overfeeding a plant will likely result in nutrient burn, causing the plant’s leaf tips to turn yellow or brown. Left unchecked, nutrient burn will hinder growth and yield. Underfeeding will also affect the plant's ability to reach its full potential.
Young cannabis sativa plant in its first weeks of growing. Yellow leaves could be a sign of chlorosis or unbalanced water pH. – Moha El-Jaw/Shutterstock
“When you’re talking about changing your acidity like that, it’s complex. Often, they’re hybrid plants, so they're not true indicas or sativas,” he adds. “It becomes difficult to start playing with that too much.”
Everything is fine, should I worry about pH?
Sum mary: What You Need to Remember About pH & Growing Cannabis
All testers come with step-by-step directions that tell you exactly what you need to do to make sure you pH tester is accurate for years to come.
The amount of pH Up or Down you add will vary a lot depending on your water. If you’re using very soft water than you will need just a tiny amount of fluid to adjust the water’s pH since there’s not much “stuff” in the water to buffer the pH. However, if you’re using hard water than you’ll need to add more.
Tips for Hydroponics Growers
Common pH Problems & Questions
If you’re using a pH pen, make sure pH tester is working by testing it on 4.0 and 7.0 calibration fluid.
Maintaining pH is especially important in hydroponics. Luckily it’s really straightforward since you only have to worry about the water in your reservoir. However, if the pH is off in between reservoir changes, you can make adjustments.