Whether you’re growing cannabis in soil or with a hydroponic system, you’ve probably heard about pH testing. A good pH tester can be the difference between catching problems before they affect your plants or cause your crops to fail. Let’s discuss how pH testing works.
How Does pH Affect Cannabis Plants?
Testing pH is important for cannabis plants because different pH levels affect how well the plant can absorb nutrients.
PH stands for “potential hydrogen.” It measures of how acidic or basic substance is. The problems that arise from unbalanced pH don’t come from the kind of thing you might associate with acid – there’s no bubbling or acid burns. However, pH is related to the availability of micronutrients in the growing medium.
Something is considered acidic when it has a pH below 7. This indicates that there are lots of free hydrogen ions in the substance; essentially, it indicates that there are lots of available micronutrients such as iron. On the other hand, something is considered basic when its pH is above 7. This means that there’s a lack of available ions and micronutrients may get bound up.
What pH Should Your Cannabis Plants Have?
In general, it’s better for cannabis plants if their growth medium is slightly acidic, with a pH between 5.5 and 6.5. This keeps plenty of micronutrients available without risking iron toxicity. If the growth medium’s pH rises above 7, however, most micronutrients get bound up and plants are unable to take in the minerals that help them grow strong. Without enough micronutrients, plants can develop a range of problems and won’t grow well or support a good crop.
PH can affect both soil and hydroponic cannabis growing systems. However, the cause in both cases is usually the water used. This means that, while you can get soil pH testers if you only have soil, it’s often simpler to get a cannabis pH tester that works with water regardless of your growing medium. Water-based pH testers can be used for the water run through the hydroponic system or for the water added to the soil.
By testing your pH regularly, you can keep an eye on where your pH levels sit. This means that you can correct your pH before it starts causing problems with your plants. Correcting pH levels is much easier than managing nutrient supplementation, so testing your pH is simpler and less expensive in the long run.
The 6 Best pH Testers for Your Cannabis Plants
There are lots of kinds of cannabis pH testers out there. If you want a pH tester to help your plants grow as efficiently as possible, here are the six best options on the market.
If you’re looking for an affordable soil pH tester, the Sonkir MS02-is the best on the market. Measuring not just soil pH but also moisture levels and light intensity, this unit’s an all-around great idea. Simply insert the double stakes into the soil around your plant and select what you want the tester to measure with the easy switch on the front of the unit.
- Features: pH meter, moisture reader, and light intensity (lux) tester
- Pros: Budget-friendly, multiple features, simple to use
- Cons: Analog dial is small
- Current price: $10.99
If you want to spend a little more money for a water pH tester, the Bluelab pH pen gets great reviews. You can calibrate this model on your own, to make sure that it’s always going to give you accurate results. It also allows you to change the units in which your cannabis pH tester measures the temperature. It’s fully waterproof as well, so there are no fears about dropping the device while testing your water.
- Features: Measures pH and temperature. Backlit screen.
- Pros: Pocket-sized, multiple features, waterproof
- Cons: More expensive than other options
- Current price: $72.69
For ultimate accuracy, the AI311 water pH tester is your go-to choice. It measures pH to the second decimal point, better than any option on this list. It also measures temperature and notifies you if the pH is significantly outside of normal ranges. It even shows you when readings have stabilized, so you know your reading will be accurate every time. The fact that it’s waterproof is the cherry on top.
- Features: Replaceable probe, automatic calibration, comes with storage solutions and batteries.
- Pros: Convenient, alarms if pH is out of range, very accurate
- Cons: Expensive
- Current price: $79.75
If you don’t need quite the horsepower of the AI311 or the Bluelab PENPH, then this tester is a great midrange pH tester for hydroponic setups. It measures 0 to 14.0 pH and its accuracy is ±0.1 pH, ±0.5˚C, so it’s still plenty accurate for most cannabis growers, and it measures temperature as well. It can be calibrated and comes with calibration solutions and a rugged carrying case.
- Features: Calibration setup, storage solution and batteries included, pH testing to 1 decimal place.
- Pros: Great, accurate pH tester that’s less expensive than other water pH testers.
- Cons: Not as accurate as the AI311, no pH alarms if in an extreme range.
- Current price: $45.77.
Measuring and maintaining the correct pH for your cannabis plants is crucial to having a successful harvest. And remember, the more closely you monitor it, the less work you’ll have to do to make corrections should things get out of balance.