Measure the pH after you add any nutrients or amendments as they will change the pH value of your water. After you mix the solution, use the pH meter or drops to test the pH level. If you are growing hydroponically, test a sample from your water reservoir a few minutes after you add your nutrients.
In more scientific terms, pH level has to do with the concentration of hydrogen ions, say in the water you give to your plants. The pH scale is logarithmic to the base 10, which means that water with a pH of 6 is already 10x more acidic than water with a pH of 7.
As you will already know, all plants require nutrients for healthy growth. They require macronutrients nitrogen, phosphorus, and potassium, as well as micronutrients and minerals including calcium, magnesium, iron, copper, and a whole lot more. If plants cannot access these nutrients, it will lead to deficiencies and other serious health problems.
If you grow purely organically—where you do not administer liquid nutrients—pH is less of an issue. If you’re using amended and composted soil with organic matter, the microorganisms within will make the nutrients more available to the roots. However, most growers using standard potting mixes and liquid nutrients will indeed have to reckon with pH.
pH is a measure of how acidic or alkaline something is. The pH scale ranges from 1–14, with a pH of 7 being neutral (the pH of pure water). If pH is lower than 7, a substance is considered acidic (think vinegar or lemon juice). If the pH is higher than 7, the substance is alkaline, as is the case with soaps, bleach, and ammonia.
If the pH is out of the optimal range for your growing setup, it’s crucial you correct it. This can be done using “pH up” and “pH down” products, which you can obtain at any grow store. If your pH is too high, you will of course need to add some pH down, and vice versa.
HI-98107 pHep pH tester provides fast and accurate pH readings. The easy-to-use device is designed for non-technical users, and can help both novice and advanced growers measure water pH.
With these methods, it is just as important that you allow the pH level to fluctuate across the acceptable range to support nutrient uptake. For example, in hydro, calcium and magnesium are mostly absorbed at pH levels above 6, while other nutrients like manganese prefer a slightly lower pH.
To test pH, you can use a digital pH meter, or a pH measurement kit with drops. Opinions here differ as to which method is “best”. Some prefer digital pH meters because they are accurate and easy to read, while others like the drops as they are super simple and don’t require calibration. Try them both and see which you prefer.
In the world of gardening, pH both affects and is affected by everything. Indeed, the entire process of growing plants is a study in the physical dance of pH balance.
“It’s something that’s misunderstood, often overlooked, and it’s highly important,” says Nico Hach é , one of the program’s instructors and a horticultural consultant with Root to Shoot Solutions. “People talk about nutrient lock out, that’s generally pH related.”
“With a nine-week flowering or 10-week flowering plant, I would peak around the fourth or fifth week and then begin to tone it down, so you can start your flush at the end. You slowly creep up,” says Hach é.
While many nutrient companies add pH stabilizers to their products, Hach é recommends frequent water testing to ensure pH remains in the ideal range.
To find out what’s right for the strains in your garden, Hach é recommends starting with a low nutrient concentration in the cloning or seed phase of growth. The EC should gradually increase as the plant matures.
“A range allows marijuana to absorb what it likes,” says Hach é. “Your pH doesn’t change your concentration of nutrition, it changes the availability of nutrients. Even though the nutrients are there, they might not be up-taken, or they may be absorbed in excess.”
The EC should peak about halfway through the flowering stage of growth.
“When you think of the regions of the world where these plants come from, they’re complete opposites. All the factors would be different,” Hach é says. “Y ou can treat them exactly the same, they’re both marijuana plants, but you could probably be a little more efficient by fine-tuning indicas or sativas.”
However, matching pH to the plant’s natural environment could help promote native characteristics, like terpene profiles.
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.
Want healthy, productive plants? Dial in your potential hydrogen and you’ll be on your way to a thriving crop.