Read the Shocking Truth About pH Meters for Marijuana Growing!

I’ve got a battered old box on a shelf in my grow room that’s marked “Meter Graveyard.” It’s piled high with a couple thousand dollar’s worth of useless Oakton, Hanna, Bluelab, Milwaukee, Vivosun and other commonly-used brands of pH meters and probes.

You and I know that the pH of our nutrients solution, root zone media, and foliar sprays are a crucial measure of the acidity-to-alkalinity scale—if nutrients solution and root zone pH don’t stay in a very narrow range, the following bad things can and usually do happen:

  • Your plants can’t root-absorb all or enough of the 13 essential nutrients they need for survival, healthy growth, and big yields of potent buds.
  • Roots suffer and in some cases die.
  • Root zone beneficial microbes that help roots will die. Pathogenic microbes flourish.
  • Plant growth stalls. Buds and resin glands won’t develop properly. Harvests will be light.
  • In pure hydroponics such as deep water culture, aeroponics, and rockwool, it’s relatively easy to flush the root zone and reset bad pH. But in other types of growing, including soil, soilless mix, and coco coir, it’s hard if not impossible to flush and correct root zone pH. Entire crop cycles can be ruined.
  • If your foliar spray is the wrong pH, you burn your cannabis leaves.
  • If nutrients water with incorrect pH is given to early seedlings and clones, it can permanently stunt the plants so they never recover.
  • Incorrect pH wastes your nutrients and reverse osmosis water. Plants ruined by bad pH equals a lost season with pathetic return on investment.

There are several reasons your nutrients water and/or root zone pH could be out of the narrow 5.7-6.1 range that assures optimal absorption of all nutrients elements your plants need. If you’re using soil, soilless mix, or coco coir, bad pH often happens because the manufacturer did incorrect mixing and pH buffering of the root zone material you’re using. Many manufacturers of commercial soils and other root zone material sold to cannabis growers don’t seem to know how to create stable pH in their products.

Other pH problems come from your fertilizers. Whether they’re synthetic hydroponics base nutrients or so-called organic or natural fertilizers, most fertilizer manufacturers who sell to the cannabis industry aren’t using the best materials or methods for assuring consistent pH, especially if the nutrients solution is used for several days in a recirculating reservoir.

For example, most nutrients companies use carbonates or bicarbonates as so-called “pH buffers” in their hydroponics base nutrients. Not only do these compounds create feed problems, they tend to create irrevocable alkaline spikes that wreck your root zone pH and harm your marijuana plants.

As your plants use varying amounts of nutrients elements due to natural nutritional needs, nutrients mix pH changes. Very minor fluctuations in reservoir nutrients solution pH usually aren’t harmful, but poorly-made nutrients products with inferior pH stabilizers often create major pH fluctuations as plants draw nutrients from the water, resulting in a spiral of pH problems that build on each other.

Also, if you use anything other than reverse osmosis water for your nutrients mixes, you’re almost certain to have pH problems, along with crop damage coming from heavy metals, pesticides, herbicides, iron, calcium and other materials in most generic non-RO well-water and municipal water supplies.

What took me a long time to figure out is most of my pH problems were happening because I was using defective pH meters, pH calibration solutions, and pH probe storage solutions. This revelation came after I’d almost gone crazy doing flushing, changing nutrients brands, trying new grow op systems, testing runoff pH and otherwise attempting to figure out why my leaves had symptoms of nutrients problems…but I didn’t suspect my pH meters were the real problem.

I was naïve and trusting, believing that pH meter models and brands I purchased after seeing them used in other grow rooms run by successful professional growers were working fine for me. But when I realized my marijuana plant problems couldn’t have been caused by anything other than bad pH, I started testing my meters against each other and was disgusted to discover that no two meters, even the exact same model, read pH exactly alike. Nor did they calibrate identically.

Another unpleasant surprise: different brands of 7.0 and 4.0 pH reference and calibration fluids gave me different meter readings. I also discovered that different brands of KCL pH meter probe storage solutions had different pH and parts per million properties, and some of them destroy your pH probes.

Pretty soon, I was calling the major well-known pH meter manufacturers to get answers about these frustrating problems that were robbing me of my heaviest, most profitable harvests. I owned their gear, some of it was under warranty, and I wanted answers and replacements. What I got instead was pushback, dishonesty, evasion, and rudeness.

One manufacturer told me the $105 portable meter I’d purchased was “never meant to be precise.” It’s only accurate within plus or minus .4 either way, he said. So when that meter said 5.7, the actual pH of the solution could be 5.3 or 6.1, with 5.3 being way too acid for cannabis plants.

The most disappointing responses came from Bluelab. I’d long believed that their expensive Combo meter, which measures pH and EC/parts per million, was the most reliable portable meter available for less than $400.

When I first started buying Combo meters more than a decade ago, they cost $140. Now they cost nearly $400. But that’s not because the meters have been improved. In fact, based on the pile of dead Combo meters in my Meter Graveyard, the quality of Bluelab meters has gone down as the price has gone up.

Bluelab Combo meters come with a 5-year warranty, and it used to be that when your Combo meter failed during the 5-year warranty, Bluelab would happily send you a new one. But when my year-old Combo meter failed earlier this year, Bluelab said I’d have to send it to their repair depot at my own expense so they could test it. Maybe they’d repair or replace it then, they said, maybe not.

I asked them what I was supposed to use as a meter while the broken one was away. They said I should buy a backup Combo meter. They want me to spend my money on two meters just to ensure I have one that works!

That was the final straw for me. I realized I’d been a fool to trust Bluelab or any of the other meter companies I’d tried so far.  I vowed to do and spend whatever it takes to get a totally reliable, accurate pH meter made by an ethical manufacturer. I love giving my plants the most ideal feed program possible. So I want a pH meter that can satisfy my demands for precision and reliability.

I called friends who work in multi-million dollar licensed commercial cannabis grow ops, the kind where they can’t risk having bad pH because it would cost them piles of money.

Some of them told me they use professional industrial meters that cost $1000 or more, and are placed in-line with dosimeters and other complicated, automated fertigation equipment that’s way too advanced for my needs. I didn’t have enough money.

Finally, I got a recommendation that turned out to be worth gold. I was told that an American company named Apera makes incredibly accurate and reliable meters, and that Apera is a family business that takes its responsibilities as a manufacturer and its obligations to its customers very seriously.

I immediately contacted Apera. The first thing I noticed was their employees are friendly, candid, and extremely knowledgeable. I explained the many problems I had with other pH meter brands and they gave me solid reasons why theirs don’t have those problems:

“We are a family-owned small business with 75 employees worldwide focusing on the highly technical field of electrochemical sensors and instruments for almost 30 years,” explained Apera spokesperson Chandler Wu. “Our ISO 9001:2015 certified manufacturing base is located in the Cao He Jing industrial park in Shanghai, China. This is one of the most advanced industrial areas in the world; we have neighbors like 3M and Mettler Toledo. At least 60% of our factory workers have been working with us for more than 15 years.

We’re proud that we design and produce every important meter component of our products in-house, so we have total control over product quality. Some meter companies outsource manufacturing of their key components to third-party companies, which often leads to serious quality control issues.

We’re also proud of our customer service flexibility and responsiveness. As a small company with the feeling of family and teamwork, the meaning of our existence is to make our customers happy and help them succeed in their projects by using our meters. More revenue and profits are never our top priority. We take every customer’s feedback seriously, and this often helps us improve our meters.”

After talking to other professional marijuana growers, and researching the company’s reputation and products online, I noted two Apera meters especially appropriate for marijuana growers.

One of them is a type of pH meter I’ve never tried before. It’s called a “benchtop meter,” and as soon as I started working with it, I realized that its precision, algorithms, probes, calibration fluids, calibration procedures and accuracy are 1000% better than any of the meters I’ve used before, including the Bluelab Combo that costs way more.

The meter uses three-point calibration with stops at 4.0, 7.0 and 10.0–a far more reliable calibration protocol than the one-point or two-point calibration other meters use.

Because the meter measures to the hundredth decimal place, I was able to see subtle but important details. For example, a nutrients solution that read 6.0, 5.8 or 5.7 pH on my Bluelab and Hanna meters was actually 5.57 pH. This might seem like too subtle a difference to care about, but when you’re growing in pure hydroponics such as rockwool or deep water culture, a “subtle” metering error can determine whether your plants absorb enough of all nutrients elements, or whether some are left behind because the solution is outside pH range.

Another thing I love about my Apera PH700 meter is it runs on wall current instead of batteries. My previous meters all ran on batteries, and would shut off automatically while I was still metering. Plus, they used up batteries quickly, which cost me extra money.

Apera is aware of what other meter companies don’t seem to know or care about: pH meter probes can’t accurately measure pH in reverse osmosis, distilled or very-low-ppm water.

When you’re giving nutrients to new seedlings or clones, or when you’re making foliar sprays or flushing solutions, your nutrients doses are so low that the solution is often less than 150-200 parts per million, if that much. Regular meters, including the expensive Bluelab Combo, give inaccurate readings in those situations. Apera makes a special probe for low-ppm solutions, and it works perfectly.

I’m saving up my money to get a completely different Apera meter—the PH850-SL portable. It comes with a spear-tip pH probe backed by Swiss sensor technologies, which enables nutrients solution pH testing and direct test of soil or rockwool pH–you simply insert the spear-tip probe into the root zone and get the measurement.

Those of you who have struggled like I have with measuring runoff pH, trying to create “soil slurries” to measure soil pH, and using other brands of so-called soil pH meters will rejoice at finally being able to accurately meter your root zone.

And being able to meter a rockwool root zone is a huge plus. The only time I ever saw anyone doing it accurately, they were using a $2500 handmade meter that kept failing due to electrical problems. Root zone pH can be a nightmare, but the Apera Ph850 is a sweet dream that’ll bring your pH nightmares to an end.

For those of you with other brands of pH meters who feel your pH meter and garden performance are acceptable, I urge you to try the pH700 or the 850 and find out what you’re missing.

What you don’t know can hurt you, especially when what you don’t know is that your pH meters are giving you inaccurate readings. I didn’t know my old-school pH meters were misleading me, and for every fraction of a percent that my pH deviated from 5.7, I was losing maximal nutrients absorption. This translates into losing maximal growth rate, plant health, and bud/resin production. In other words, losing money!

To be brutally honest, the Hanna, Oakton, Milwaukee, Bluelab and other meters I used before are mere toys compared to Apera gear. I’m very upset with myself that I wasted so much money, time, and crop potential for so many years using those inferior meters and their unreliable probes.

The insidious thing about pH meter problems is your plants might perform well enough, but you don’t realize your meter is off by 5-15% or more deviation from actual pH, resulting in incorrect nutrients solution pH that costs you a significant amount of growth rate, resin production, and harvest weight. With pH, a little bit of error goes a long way when it comes to robbing you of maximum crop return on investment. That’s why you need a rock-solid pH meter.

Apera meters offers functions that are fun to use and very helpful grow room tracking. These include data logging, automatic adjustment based on solution temperature, auto-diagnosis so the meter tells you when its algorithms, electronics or probe are failing, and many other practical features. And as you’d expect, Apera also offers precision EC meters and dissolved oxygen meters very useful for marijuana growers.

In a greedy world where most pH meter companies are making generically inferior units that don’t give precise measurements, refusing to honor warranties, and interested only in profits, Apera is a sincere, ethical company owned and run by people dedicated to ensuring that you have the most accurate pH measurements possible.

Here’s an example of how ethical and customer-centered Apera is—when I asked Chandler Wu about ordering gear from the Apera website, he said I could do that, but prices are lower on Amazon. That’s the first time I’ve met a businessperson who told me how to spend less money on their products!

The problems you experience in your grow op caused by inaccurate, unreliable pH meters will go away when you use Apera gear to get total accuracy for the first time ever. When you dial your nutrients solution and root zone to the ideal pH for nutrients absorption, you’ll see faster growth, and heavier, more potent yields. Anyone serious about growing marijuana, whether you have a one-light tent or a 100-light commercial grow op, can trust Apera like we do.

Their world-class, reliable, innovative meters will increase your grow room success, lower your gardening stress, and put the joy back into pH monitoring and adjusting! The entire grow team here at Growing Marijuana Perfectly is united in encouraging you to contact Apera and tell them what kind of growing style and system you have, and get the meter(s) they recommend for you. It’s a wise investment that definitely pays off for you and your marijuana plants.