Finding the best pH meter is quite a chore. In fact, hydroponic gardening, in general, can feel a lot like an undergraduate-level science class at times!
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Unlike soil-based gardening, growers need to keep track of every little detail. Your water quality, and especially the pH level of your nutrient solution, is vital to track. Failing to properly monitor your nutrient solution can result in sickly plants and a healthy dose of frustration.
When I first got into hydroponics, I didn’t take my water quality seriously. After all, in traditional soil gardening, a stockpile of lime and compost kept my soil pH right where I wanted it. But in hydroponics, you’ll need a little more attention to detail. So investing in the best pH meters for hydroponics to check your values makes lots of sense!
9 Best pH Meter Reviews
Bluelab pH Pen Pocket Tester
The Bluelab pH pen is the best pH meter for hydroponics out there. It measures pH and water temperature, and the back-lit LCD display makes it easy to read. I’ve written a more in-depth review of the Bluelab pH pen here, but the basic idea is that it’s my favorite digital pH meter and the one I use in my gardens on a daily basis.
- Measures pH in nutrient solution (acid or…This hydroponics tester has ATC that provides…Double junction electrode has a longer lifespan…
Pros
- Easily measure pH and temperature with one readingFully waterproofSponge in cap to keep the probe moistComes with 1-year limited warranty
Cons
- Calibration kit not includedFragile sensor bulbs
Hanna Instruments HI 9813-6N pH/EC/TDS Meter
If for some reason you don’t like the Bluelab line, the Hanna combo meter is a great alternative. Hanna is another extremely reputable manufacturer of pH and combo meters, and although I personally use Bluelab, many of my friends are devoted Hanna fans.
- Starter set with portable, water-resistant meter…Calibration check function to validate instrument…Automatic temperature compensation (ATC) to…
One of the best features in this combo meter is the built-in calibration reminder. No more forgetting to calibrate and wondering why your readings are so off!
Measures pH, temperature, electroconductivity (EC), and total dissolved solids (TDS)Easy to read displaySimple operation and calibrationBuilt in calibration reminder7.0 and 4.0 calibrationWaterproof
Cap has no seal lockNo anti-slip feet
Bluelab Combo pH Meter
The Bluelab Combo Meter is the de-facto standard in combination pH, temperature, and PPM/EC/TDS meters. It’s the one that I recommend most often as well as the one that I find most growers to be satisfied with.
Monitor 3 parameters in water: Conductivity (TDS)…This hydroponics meter has ATC that provides…Combine with Bluelab meters and controllers for…
Measures pH, temperature, and electroconductivity (EC)Comes with replaceable double junction pH probeAuto off functionAutomatic calibration
Fragile probeNot completely waterproof – only the probes are
Apera Instruments AI311 Premium pH Test Kit
While it requires some specific care and maintenance, this pH water tester is a great option. Apera Instruments has a number of different models (as you’ll see further on), but this one is their top of the line. It comes as a complete kit including calibration solutions, a quality glass probe, and even storage and battery options.
NOTE: A few drops of water are added to the…Accuracy: 0.01 pH; range: -2.00 to 16.00 pH, 32 to…Easy 1-3 points auto. calibration, recognizes 5…
Easy calibrationReplaceable probe3-color LED window identifies each mode of operationFully waterproof
Must be protected from freezing conditionsReplacement probes can be pricey
Oakton EcoTestr Pocket pH Meter
The Oakton EcoTestr is an old standard for a pocket-sized ph tester. While it’s often forgotten when newer devices are unveiled, I find it to be a reliable option that’s usually a few dollars cheaper than newer models.
Batteries: 4 A76 1.5V miniature alkaline batteries…Buffer recognition: nist and usaCalibration: up to 3 points
Good budget optionMeasures pH and temperatureWaterproof and dust proofConvenient pocket size1-year limited warranty
Doesn’t last as long as the Bluelab pH penMust keep calibrated more often
Bluelab Guardian pH Monitor
The best combo meter is the Bluelab Guardian Monitor. This meter is pricier than the other options but is ideal for serious growers with a large budget. Because it’s always on and monitoring your garden, you’ll know the instant that your metrics get out of whack.
- Monitor pH up and down, temperature, nutrient…This hydroponics tester has ATC that provides…Lab quality glass pH probe with easy two point…
If you are a larger-scale grower with some money to invest in your monitoring system, then you absolutely must go with the Bluelab Guardian. I know of no other good solution for this level of live-monitoring.
Large displaysFlashing alarms if numbers are out of rangeComes with a range of accessories
Sometimes the digital displays bug out (only a few reports of this)You can burn through probes quickly without proper care and calibration
Apera AI209-T Value pH Test Kit
The Apera Instruments AI209 is their value-level test kit, and it’s a surprisingly popular one. This pH tester for water is portable and easy to use. The kit includes all of the necessary calibration solutions to ensure you’ve got accurate readings. If you’re looking for something inexpensive but all-inclusive, you can’t go wrong with the Apera Instruments AI209.
The top-rated pH tester now comes with a complete…Comes with a probe cleaning brush for easy removal…Comes with Apera’s unique CalBox, heping you…
Easy to calibrateOffers dual display of water temperature and pH levelComes with probe cleaning brush & calibration solutionsFully water and dust proof
Can get bubbles in the probe sensor that need to be dislodgedTakes about 30 seconds longer than manufacturer says for readings
Apera SX620 pH Pen Tester Kit
This narrow Apera Instruments pen tester has a narrow probe that easily tests the pH level in everything from test tubes to large reservoirs. As with the other Apera Instruments devices we’ve covered, this device comes with a full kit and will require regular calibration. Pocket-sized, it’s a great small device for keeping tabs on your solution.
The smallest pH pen with reliable testing…0. 01 pH accuracy; Automatic 3-point calibration;…Slim replaceable probe, suitable for test tubes
Slim, replaceable probeIncludes calibration solutions, pocket-sized storage case, storage solutionFully dust and waterproof, floats in water
Small screen can be difficult to readTakes a little longer than expected to test pH levels
Dr. Meter Digital pH Meter
If your budget is a bit too low for the other pH testers on our list, consider this Dr. Meter hydroponic pH tester. It tests both temperature and pH levels at a budget price. While not as fancy or specialized as some of the pricier options, the Dr. Meter device is a reasonable choice.
【BEFORE USE】: Get some potassium chloride…【DURING USE】: If there is inaccurate…【AFTER USE】: To ensure the activity of the…
Extremely well-priced for a decent meterEasy to calibrateHas a nice large screen that’s easy to see
Batteries are a bit difficult to installReplacement probes do not appear to be available
Helpful pH Testing Accessories
After dropping a large sum of money on a digital meter, I’m sure that the last thing you want to think about is buying more accessories.
Unfortunately, your meter won’t be much use to you without a calibration solution and care kit. These kits help keep your pH meter accurate and operational, giving you better results and preserving your investments.
Bluelab Probe Care Kit
If you decided on a digital pH meter from Bluelab, their probe care kit is both affordable and the best option. It’s designed to work with the full range of Bluelab products and comes with a bottle of 4.01 reference solution and 7.0 reference solution, available in 8 oz and 1-quart quantities.
Designed for use with Bluelab productsComes with probe cleaner, tool, and plastic cups
Only comes with 2 x 20ml sachets
General Hydroponics pH 4.01 & pH 7.0 Calibration Solution
General Hydroponics also has a kit that comes with one bottle of pH 4.01 solution and one bottle of pH 7.0 solution. This is a good option if you either don’t have a Bluelab meter, or you just want a large quantity of solution without any of the extra bells and whistles.
General Hydroponics is a highly reputable brand in hydroponicsYou get much more for the money
Does not come with cleaning supplies
All of this might seem like a lot of information to take in, but I promise it is worth it.
Monitoring the pH of your hydroponic solution is the single most important thing you can do to ensure a thriving crop and happy plants.
To do that, you need the right tools, and you need to know how to care for them.
One of the things I have learned as a gardener is that there are two things that can ruin a tool: buying a cheap, poorly made product and failing to care for it properly. If you have invested time and money into your hydroponic system, don’t waste it by buying a cheap pH meter.
A good meter will pay back your investment, and a bad one will cost you more in the long run.
Why Monitoring Your pH is so Important
So why does pH matter? The pH of any growing system, be it hydroponic or soil, plays a large role in the growth of your plants. It’s not just a matter of some plants preferring more acidic soils or other plants preferring more alkaline – it determines the nutrients that are available to your plants.
Look at it this way: you take the time to ensure your plants get all of the nutrients that they need. But none of this matters if your pH is off. Unless your test shows you’re in the right range, your plants won’t be able to absorb the nutrients, which means you have wasted time and money adding them to your system.
Still confused? Check out my article on pH and nutrient availability for a complete breakdown of the relationship between pH and nutrient availability.
But for now, what you need to know is that it matters, and you need to monitor it.
Most plants do well with a pH of 5.5 to 6.5. While some plants have specific requirements, a good rule of thumb is to stick to the “sweet spot,” which is around 6.2.
Keeping your system slightly acidic has another advantage as well: many waterborne algae varieties don’t like acidic environments. Since we don’t like waterborne algae, this is a win-win situation.
How Does a pH Meter Measure pH?
Now that we agree that monitoring pH is crucial to the growth of your hydroponic garden, let’s talk about how these meters work.
Your pH meter measures the hydrogen-ion concentration of your water. This concentration indicates whether the solution is acidic or alkaline by determining the difference of the electrical potential between a reference electrode and a test electrode.
Personally, my brain has a hard time wrapping around this sort of thing, so I’ll keep it simple. Your meter has a glass electrode, which is sensitive to hydrogen ions, and a reference electrode, which is stable. The difference between the two tells the pH meter what the pH of the liquid is and allows you to adjust your solution accordingly.
Manual pH Testing vs. Digital pH Meters
There are two basic types of pH meters: manual and digital. If you are a serious hydroponic grower, then you probably already use a digital pH meter. If you are just getting started, though, I will give you the breakdown of the pros and cons of manual pH testing vs. digital.
Manual pH testing
Manual pH testing is done with a simple kit, kind of like the water pH test kit you use to test the pH of a pool. Manual water pH test kits are much cheaper than digital pH meters and they are easy to use.
Upsides to Testing Your pH Manually
Since there are no parts to a manual pH kit that require care, you don’t need to worry about things breaking or corroding over time. These traits make manual testing kits ideal for growers just getting started in hydroponics.
Downsides to Manual pH Testing
The downsides of manual pH testing make them less than ideal for serious growers. It takes a lot more time and effort to work with manual pH test strips or pH fluid.
Time management becomes a barrier to serious growers, especially when compared to the simplicity of a digital pH meter.
Accuracy is also an issue. pH strips can be hard to read, especially if you are color blind. This can lead to readings that are way off, which will negatively impact your system.
Digital pH meters
Digital pH meters are the way to go it you plan on doing a lot of hydroponic growing. These meters should last a lifetime if you take care of them, and they are much more accurate than manual pH meters and pH test strips if they are calibrated properly.
Digital meters are fast, too, letting you test quickly and frequently, making them far more efficient than manual pH meters.
Downsides to Digital pH Meters
Of course, all of this convenience and efficiency comes at a price. The best digital pH meters are more expensive than manual pH meters, and they also require more maintenance than manual meters.
Digital pH meters must be calibrated frequently in order for them to remain accurate, and without proper care, your expensive digital pH meter breaks down.
Calibrating a pH Meter
If you choose to go the digital route, as most of us eventually do, you need to know how to calibrate your pH meter. Think of calibration like tuning a musical instrument. You need things to be tuned to the right key, or the entire musical piece will be off.
Before you begin, you need a buffer solution. A buffer solution is basically a laboratory certified standard reference point for your pH meter. Most buffer solutions are liquid, although you can buy them in powder form and mix them with water if you prefer.
Once you have your buffer solution, follow these steps to calibrate your pH meter:
- Place your meter into the buffer solution to get accurate readingsAdjust the reading on your meter to match the buffer solution according to the manufacturer’s instructions (these can differ for digital and analog meters)Repeat if necessary in an additional buffer solution of a different pH for higher accuracyCalibrate your pH meter once a week if you use it regularly, or at least once a monthAlways calibrate your pH meter when you replace a sensor for accurate readingsYour pH meter will come with instructions. Make sure you read them before calibrating your meter just in case the steps are different.
Caring for your pH Meter
All of that calibration won’t matter if you don’t take the time to care for your pH meter.
As boring as most directions usually are, the first thing you should do when you get a new pH meter is read the instruction manual that comes with it. The instructions should tell you how to care for your pH meter. If they don’t, call the manufacturer and ask them.
In general, there are several things you need to do for every pH meter:
- Read the instructionsKeep it calibratedStore meters with storage solutions in the cap upright for optimum saturationLightly swirl your meter in the storage solution to get rid of air bubblesDon’t touch the sensor electrode or reference cell, as the oil on your skin can damage the sensor and affect readingsStore away from high heat and humidityDon’t store your sensor in distilled waterHandle with care
