Managing pH levels in your aquarium is crucial for keeping your fish, invertebrates, and aquatic plants happy and healthy. These levels should be monitored regularly so you can identify any changes and resolve them before it’s too late.
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However, it’s impossible to identify the pH of your tank water simply by looking at it, so you’ll need something to test it for you. While you can use liquid tests and strips, these aren’t as accurate or long lasting as a digital pH meter.
I used to use liquid test kits for my tanks, but I found them to be imprecise and poor value for money (the liquid eventually runs out after all!). As I have several aquariums and measure my pH values every week, I was buying pH test kits on a monthly basis.
I wish I’d discovered digital pH meters sooner as it would have saved me a lot of money in the long run.
But not all aquarium pH testers are effective, especially if they’re poorly constructed. That’s why I’ve compiled a list of the best aquarium pH meters to help you find the right one.
Best Aquarium pH Meters
Here’s a quick look at the 3 best aquarium pH meters from our list…
Apera Instruments Sx620 pH Pen
The Apera Instruments Sx620 pH Pen Tester Kit boasts 0.01 pH accuracy and 3-point calibration for reliable pH value results.
Top Pick: Apera Instruments Sx620 pH Pen
My top pick is the Apera Instruments Sx620 pH Pen Tester Kit as it accurately measures pH and comes with a huge range of features, such as auto pH temperature compensation, an auto turn-off function, and even a probe replacement indicator.
The best pH meter for aquarists on a budget, in my opinion, is the PmoYoKo Digital PH Meter with 0.01 pH accuracy. Not only is it extremely affordable, it provides you with reliable readings.
Best Value: PmoYoKo Digital PH Meter
If you need a functional pH meter that’s also budget-friendly, I think the PmoYoKo PH Meter is a solid choice. It’s easy to calibrate thanks to its automatic calibration feature, allowing you to measure your tank’s pH with confidence.
My personal favorite pH tester is the Bluelab Combo Meter as it measures TSS, (total dissolved solids) EC, temperature, and pH. Its probe is made from lab-grade glass so you know it’s built to last.
Editor’s Choice: Bluelab METCOM Combo Meter
If you can afford to spend a bit extra on a pH meter for your tank, the Bluelab METCOM Combo Meter is worth considering. It’s made from lab-grade glass to ensure its longevity and comes with many useful features like a low-charge indicator and calibration reminder.
Top 8 Aquarium Digital pH Meters
Let’s proceed with the full reviews of all the items in the list…
Apera Instruments Sx620 pH Pen Tester Kit
The Apera Instruments Sx620 pH Pen Tester Kit boasts 0.01 pH accuracy and 3-point calibration for reliable pH value results.
Top Pick: Apera Instruments Sx620 pH Pen Tester Kit
Replaceable Probe
It has a slim replaceable probe so you can switch it out for a new one when it breaks.
Not all pH testers have a replaceable probe, which means you have to purchase a new unit when it becomes defective.
It’s great that the Apera Instruments Sx620 doesn’t have this problem as it saves you the hassle (and the money) of buying a whole new product!
Features
The Apera Instruments Sx620 has many advanced functions, which is why it’s my top pick overall. It is able to switch from Fahrenheit to Celcius, which is helpful if you need to convert to either. It also automatically powers off if it’s left on and notifies you when it’s time to change the electrode.
Inclusions
Also included with this pH Pen Tester Complete Kit are 3 types of calibration solutions (4, 7, and 10) and a storage solution case.
Despite its huge number of positives, the Apera Instruments Sx620 pH Pen Tester Kit can sometimes have inconsistent pH results. Calibrating the device frequently could help make it more reliable. The digital display can also be a bit blurry, making it difficult to read.
Specs
- Color: White
- Item Weight: 5 0z
- Item Dimensions: 6” x 1” x 1”
- Power Supply: Cell Battery
Pros
- Replaceable electrode
- Provides accurate readings
- Includes 3 types of pH calibration solution and batteries
- Advanced functions such as probe replacement reminder
Cons
- LCD display can be a bit blurry
- PH reading can sometimes be inconsistent
The best pH meter for aquarists on a budget, in my opinion, is the PmoYoKo Digital PH Meter with 0.01 pH accuracy. Not only is it extremely affordable, it provides you with reliable readings.
Best Value: PmoYoKo Digital PH Meter
Features
It has automatic calibration so you don’t need to do it manually, as well as an automatic temperature compensation feature. I like the compact size of the device and the backlit LCD. You can also use the cap of the device to hang it on a lace or string to make it easier to carry around.
Inclusions
This pH testing device from Pop V also has an on/off button, battery case, and backlit LCD screen so you can easily read the pH value of your tank. Alongside aquariums, the pH tester can also be used for drinking water, hydroponics, well water, and pools.
Unfortunately, the unit can stop working after a few months and eventually lose the ability to calibrate. That said, I think it’s still a decent choice if you need an inexpensive pH tester.
Specs
- Color: White/Grey
- Item Weight: 5.29 oz
- Item Dimensions: 1.38 x 1.38 x 7.2 inches
Pros
- Compact size
- 0.01 pH accuracy
- Auto calibration
Cons
- Can suffer from durability and calibration issues
My personal favorite pH tester is the Bluelab Combo Meter as it measures TSS, (total dissolved solids) EC, temperature, and pH. Its probe is made from lab-grade glass so you know it’s built to last.
Editor’s Choice: Bluelab METCOM Combo Meter
Features
The digital pH meter has two-point easy calibration and automatic temperature compensation for high accuracy, as well a digital display and calibration reminders.
While these are all useful features, I particularly like the device’s auto-off function and low battery notifier.
As someone who often forgets to turn electronic devices off, this is a feature I’d find really helpful. It also prevents you from draining the battery.
Inclusions
The Bluelab Combo Meter includes AAA batteries and calibration solution so you don’t need to purchase these two products separately. It even has a 5-year limited warranty, which is longer than what most companies offer for their pH meters.
You definitely don’t need to worry about poor customer service with Bluelab.
Reading
My main gripe with the unit is that it can take a while to deliver pH readings (occasionally up to 4 minutes). This is a little longer than most devices, which usually take around a minute. It can also become hard to calibrate over time.
Specs
- Item Weight: 5.27 oz
- Color: White and Blue
- Power Supply: 1 x AAA Battery
- Item Dimensions: 5.7” x 3” x 1.47”
Pros
- Low battery notifier
- Automatic temperature compensation
- Measures tds (EC), temperature, and pH
- Includes calibration solution and batteries as bonus
Cons
- Can take a while to deliver pH readings
- Calibration difficulty can increase over time
The Bluelab pH Pen is another solid choice for testing your aquarium water, giving your accurate readings so you can easily determine whether your tank water is acidic or alkaline. It can be used for pool water, drinking water, brewing, hydroponics, and growing too.
Bluelab pH Pen
This ph meter can be used for pool water, drinking water, brewing, hydroponics, and growing too.
However, I wouldn’t recommend using the same pH probe you use for your tank water for liquids you intend to consume (it’s unsanitary and probably wouldn’t taste very nice!).
Features
The pH meter has two-point calibration and automatic temperature compensation, which means it takes the temperature of your tank water into account to deliver precise readings. It also has a backlit digital display and calibration reminders.
I think the latter is a particularly great feature as it notifies you when you need to recalibrate the probe. Regularly calibrating pH meters is important to ensure their reliability..
Probe
I also like that the pH meter pen has a double junction probe, which not only makes it more correct, but also increases its lifespan. Some other great features include an auto off function and low battery notifier.
The low battery indicator is particularly handy as you’ll know exactly when it’s time to change the battery. No more guesswork!
However, this pH tester can sometimes become difficult to calibrate after around 6 months of use.
Specs
- Item Weight: 4.3 oz
- Color: White and Blue
- Power Supply: 1 x AAA Battery
- Item Dimensions: 8” x 2.16” x 0.98”
Pros
- Low battery indicator
- Reminds you when to recalibrate the device
- Double junction probe for increase longevity
- 2-point calibration and automatic temperature compensation for accurate pH results
Cons
- Can become increasingly difficult to calibrate over time
Dr.meter PH838 Upgraded pH meter
Another great pH meter that measures pH with high accuracy is the ph100 V Dr Meter pH Tester. The aspect I like the most about this unit is its 3-point calibration, which gives you reliable readings almost instantaneously.
Dr.meter PH838 Upgraded pH meter
Features
It has auto temperature compensation to make sure you’re getting the most precise results. Compared to some other pH meters which have a range of 0 to 50, the pH100 V Dr Meter pH Meter has a range of 0 to 70 degrees, allowing you to test most aquatic habitats.
LCD
The digital pH meter has a clear LCD screen that can be seen in even low-light conditions. In addition, if the pH reading is lower than 3.5 or higher 12.5, the white screen will flash and change to red to notify you.
That’s not all. The pH100 V meter comes with a storage case and a 15-minute auto-off function so you don’t drain the batteries.
Reading
My main concern with the Dr Meter pH tester is that it can take several minutes to deliver accurate readings.
The calibration feature can also be a bit inconsistent as sometimes it won’t work properly, requiring you to recalibrate it.
Specs
- Item Weight: 11.22 oz
- Color: White and Grey
- Power Supply: 2 AAA Batteries
- Item Dimensions: 8.6” x 3.7” x 2.1”
Pros
- 3-point calibration for accurate pH readings
- Clear LCD display that can be read in low visibility
- Screen flashes and changes to red if pH reading is too low or high
- Auto temperature compensation with a range from 0 to 70 degrees
Cons
- Calibration feature can be unreliable
- Can take several minutes to measure pH
VIVOSUN 4-in-1 Digital pH Meter
If you need a digital pH meter that can measure TDS (total dissolved solids), EC (electrical conductivity), and pH temperature value, then this one from VIVOSUN is an excellent option.
VIVOSUN 4-in-1 Digital pH Meter
Features
It has a highly sensitive electrode probe to ensure accurate pH readings and speed results. The wide measurement range and high pH resolution means it can easily measure different types of liquids, including aquarium water.
I really like how simple the pH and temperature meter is to use. Once calibrated, simply pop the sensor in your tank water to receive your reading immediately. It’s also easy to clean – just wash the probe with some distilled water and you’ll have accurate results over and over again!
Calibration
It features 3-point calibration and has a handy lock feature that locks the reading result so you don’t have to worry about it disappearing. Thanks to its green backlit LCD display, the device can be read in any visibility.
There are a couple of minor issues with this pH tester. Firstly, it isn’t entirely waterproof. And secondly, it can take a bit of time to calibrate. However, once completed, it works just as well as you’d expect it to.
Specs
- Color: Red
- Item Weight: 5.68 oz
- Power Supply: Battery (Type Not Specified)
- Item Dimensions: 1.5” x 1.5” x 7.2”
Pros
- Automatic calibration
- Measures TDS, EC, pH, and temperature value
- Includes features like lock function and green backlit LCD display
- Wide measurement pH range and high pH resolution for precise readings
Cons
- Not fully waterproof
- Not very easy to calibrate
Featuring a 0.1 pH resolution and a full pH span from 00.01 to 14.00, the Pinpoint pH Meter is a highly efficient device to test the pH of your tank water.
Pinpoint pH Meter KIT
Features
It has a lab-quality pH electrode and utilizes 2-point calibration for quick pH self diagnosis.
The instrument is completely waterproof so you can fully submerge it into your aquarium water. It’s easy to operate due to its user-friendly design, allowing you to get it set up in no time.
Inclusions
You get a wide range of accessories with the pH meter, including a 10-foot high suppression cable, BNC connector, electrode storage bottle, and calibration fluids. That’s everything you need to measure your aquarium pH.
The only fault I could find with this pH meter is its time-consuming calibration process, mostly because it needs recalibrating often (normally every week) to remain effective.
Specs
- Color: Black
- Item Weight: 14.1 oz
- Item Dimensions: 8.78” x 4.09” x 2.48”
- Power Supply: 9-volt Battery
Pros
- Completely waterproof
- Lab-quality electrode probe
- Comes with a huge range of accessories, such as calibration fluids and BNC connector
Cons
- Needs recalibrating frequently
The last pH meter in my top 8 list is the APLUSTE pH meter, sporting a bright backlight LCD screen that can be used in any visibility. It accurately detects the pH of your tank water due to its sensitive electrode sensor, giving you precise results in seconds.
APLUSTE pH Meter
Features
The ATC function means it measures the pH and temperature of your tank water at the same time, then immediately checks for any differences. It can calculate temperatures from 32 degrees Fahrenheit all the way up to 176 degrees Fahrenheit.
So, no matter the temperature of your aquarium, the Sunzeal pH tester will deliver a precise reading.
Inclusions
Included with this pH meter are a few extras like a carrying case, buffer recognition powders, and a user’s manual, which is a nice bonus.
The main downside of the Sunzeal pH meter is that it can become uncalibrated quickly, so you might need to recalibrate more often than usual.
Specs
- Color: Yellow
- Item Weight: 3.53oz
- Item Dimensions: 6.5 x 1.97 x 1.18 inches
- Power Supply: 2x LR44 Batteries
Pros
- Bright backlit LCD display that can be read easily
- Sensitive electrode for quick and accurate readings
- Automatic temp compensation for more more accurate results
- Comes with a carrying case, buffer powders, and a user’s manual
Cons
- Can become uncalibrated quickly
What Is a Digital pH Meter?
A pH meter is a device that measures the pH level of your aquarium water, allowing you to monitor your pH values without needing to use disposable test strips or test liquids.
What Is pH?
PH is the way of measuring whether a liquid is acidic or alkaline. It’s measured on a scale of 0 to 14, with 1 being pure acid, 7 being neutral, and 14 being pure alkaline.
In the wild, fish and invertebrates come from habitats with specific pH levels. It’s important to manage pH values in your aquarium to provide your fish with a healthy and stable environment.
All fish species require a specific pH, with freshwater tropical types usually preferring between 6.8 and 7.6. Saltwater species, on the other hand, typically need a pH between 8 and 8.6.
NOTE
Big fluctuations in aquarium pH levels can be harmful to your fish. In some cases, especially in sensitive species, sudden changes in pH can be fatal.
Why Use a pH Meter?
The best pH meters allow you to accurately measure and monitor your aquarium pH level. If you opt to use a pH meter, you’ll be able to identify the potential cause of a pH change and intervene before it becomes an issue.
You can get pH dip strips and liquids, but these are often less precise than digital pH meters. Test strips in particular can be unreliable as they age rapidly and are sensitive to humidity, so they can give false readings.
Additionally, digital pH meters give quicker results than pH test strips and liquids, so they save you a lot of time and hassle.
FAQS
Why Is Aquarium Water pH Level So Important for Fish?
The aquarium pH level is important to ensure good water quality, which in turn keeps aquatic life healthy. Keeping your tank within the preferred pH values of the fish species you own helps prevent stress, disease, and increases their tolerance to other stressors.
It can also improve coloration, growth, and the overall health of your fish.
Harmful pH levels
PH values higher than 9.5 or lower than 4.5 are harmful to the majority of aquatic animals. High pH values (between 9 to 14) can be fatal to fish as it denatures their cellular membranes.
Low pH values below 5 are usually lethal in fish as the acidity can cause skin burns, especially in young specimens.
What Is the Best pH Level for Aquarium Water?
There’s no best pH level as all species of fish have different pH preferences.
However, as the majority of fishkeepers house multiple fish species from different habitats, it’s best to select a pH that is suitable for all tankmates.
Most freshwater fish thrive between 6.8 and 7.8, but some fish species may have pH requirements drastically different from these values. For example, Blind Cave Tetras do well at a pH between 7.5 to 9.0, whereas Hatchetfish do best at a pH between 5.5 to 6.5.
TIP
It’s a good idea to research the species of fish you want to keep in your tank so you can check whether their pH preferences are similar.
How Often to Check the Aquarium pH levels?
I’d recommend checking your aquarium pH level once a week if your tank is established so you can identify potential issues before they get worse.
If your aquarium has only been up and running a couple of months or less, check the pH, alongside other water parameters like ammonia and nitrite, every few days.
Once your water parameters start becoming stable and your water quality has improved, you can switch to weekly checks.
How to Calibrate pH Meter
Properly calibrating a pH meter differs slightly between units, but most devices share a similar process.
- Turn the pH meter on and allow it to warm up for around 30 minutes.
- Rinse the electrode with deionized water in a waste beaker different to the one you will be calibrating in. Make sure you don’t rub the electrode as it can damage the sensitive membrane around it.
- Once rinsed, dab the electrode dry with a tissue.
- Next, place the electrode in a buffer solution with a pH of 7. Wait a couple of minutes for it to display the reading, then set the display to 7. Some meters may need more than one buffer to calibrate properly, including a solution with a pH between 4 and 9.21.
- Remove the electrode and rinse again with deionized water. Blot it dry with some tissue.
Here’s a sample of how a pH meter is calibrated.
How Often to Calibrate pH Meter?
Most pH testers need to be calibrated at least once a month to maintain accuracy.
What Raises the Aquarium Water pH?
Many natural processes of a tank can increase the pH level, including carbon dioxide and nitrates when absorbed by live plants. Calcium-rich substrate or rocks like limestone can also raise pH.
Final Thoughts
Here’s a summary of the three best pH meters from the list…
Top Pick
Out of all the pH testers I’ve looked at, I think the best pH meter overall is the Apera Instruments Sx620 pH Pen Tester Kit due to its accuracy and wide range of features.
I especially like that it has a replaceable electrode, which many other pH testers lack. It also notifies you when it’s time to change the electrode and switches off automatically when not in use.
Best Value
If you’re after a cheap pH meter, I think the Pop V Digital PH Meter is a good choice. Not only is it affordable, but it also delivers fairly accurate readings.
Alternatively, if you’re able to spend a bit more on the best aquarium pH meter, I recommend the
Editor’s Choice
Bluelab METCOM Combo Meter for pH. It’s made from high-quality materials and can measure TSS, CE, pH, and temperature.
I hope I helped you find the best aquarium pH meters. Which one is your favorite? Be sure to let me know in the comments!
If you’re looking for more detailed aquarium-related reviews and guides, check out our other posts.
