Best Digital pH Meters for Aquarium (Reviewed 2021)

Updated on January 20, 2021 by

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What Are the Benefits of Using an Aquarium pH meter?

To keep a successful aquarium running at its best with thriving fish, plants, or corals, several accessories are needed. Among the most important ones, we can mention a heater to keep the water warm at constant levels, a thermometer to keep an eye on the water’s temperature, an aquarium canister filter, or a HOB filter to clean the water of unwanted particles and control the water flow, etc.

However, some fish both freshwater and saltwater descent have special water chemistry needs and thus require a particular acidity or alkalinity level (pH level) to thrive and live comfortably. A pH level is the degree of alkalinity or acidity of a medium usually liquid and gases.

Pure water is said to be neutral (neither acidic nor alkaline) but due to the presence of impurities, the tap water pH level has been altered to either become acidic or alkaline. For this reason, measuring the pH using one of the best digital pH meters, it’s crucial to make sure we use optimal water for our fish tanks.

Should you need to checks other water parameters you can take a look at well-detailed articles about the best water test kits, or best aquarium TDS meters.

How to Use a pH meter for Aquariums?

A pH meter for aquarium is used to test, regulate, and maintain the perfect pH level required by the fish. Unfavorable pH levels can be toxic to the aquarium inhabitants and might even cause diseases, which may end up shortening the life span of the fish.

This requires that information regarding the pH requirements of your aquarium habitats should be known and the best pH meters acquired to regulate and maintain that pH level. Nowadays, many devices exist to measure the pH level of a medium, but from our reviews, a pH meter proves to be more effective, accurate, and advantageous than every other device.

Compared to other devices, a pH meter for an aquarium gives you a straightforward numerical reading that is understandable and void of any ambiguity. Unlike most pH measuring tools, the pH meter can be reused for many examinations and analyses which is more convenient and will save you money.

Also pH meters are useful for optimizing soil/water quality and for laboratory analysis as well.

This article covers a review of different affordable and easily accessible pH meters to suit your needs.

Best Aquarium Digital pH Meters Compared

ImageProductFeaturesCheck Price
Our Top Pick
Bluelab pH Pen
Bluelab pH Pen

Calibration: Automatic
Probe: Double junction probe
Functions: Auto off & low battery indicator
ATC: Yes

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High Accuracy
Apera Instruments pH Tester
Apera Instruments pH Tester

Calibration: Automatic
ph Sensor: Low impedance, high response rate
Functions: Auto off & low battery indicator
ATC: Yes

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Runner Up
Hanna Pocket pH Meter
Hanna Pocket pH Meter

Calibration: Automatic
Display: Multi-Level LCD
Functions: Auto shut-off
Indicator: Low battery
ATC: Yes

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4
Dr.meter pH Meter with ATC
Dr.meter pH Meter with ATC

Calibration: Automatic
Accuracy: Premium & fast response
ATC: Yes
Batteries: 4 LR44 batteries included

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5
HM Digital Waterproof pH Meter
HM Digital Waterproof pH Meter

Calibration: Automatic
Functions: Measures pH and Temp
Batteries: 2 LR44 batteries required
ATC: No

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6
Apera Instruments pH Pen
Apera Instruments pH Pen

Calibration: Automatic
Functions: switch from ˚F to ˚C, auto off
Probe: Slim and easy to replace
ATC: Yes

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Best Cheap
KoolaMo Digital PH Meter with ATC
KoolaMo Digital PH Meter with ATC

Calibration: Automatic
Includes: 3 x PH buffer powder
Batteries: 2X 1.5V LR44 included
ATC: Yes

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8
Bluelab Combo pH Meter
Bluelab Combo pH Meter

Measures: pH, Temp & Conductivity
Calibration: Simple two-point
Functions: Auto off & Low battery
Batteries: 2 x AAA alkaline included
ATC: Yes

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9
Apera Instruments Lab pH Meter
Apera Instruments Lab pH Meter

Measures: pH, Temp & Conductivity
Calibration: 1-3 points of automatic
Functions: Auto off & Low battery
Power Input: 120V, AC 60Hz
Power Output: 9V
ATC: Yes

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10
VIVOSUN 4-in-1 Digital pH Meter
VIVOSUN 4-in-1 Digital pH Meter

Measures: PH, TDS, EC and Temp
Calibration: 3 points automatic
Functions: Auto off
Batteries: 3 included
ATC: Yes

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1. Bluelab pH Pen Tester – Overall Best pH Tester for Aquariums

Our Top Pick
Bluelab pH Pen Pocket Tester

This pH meter is really a great handy tool and not just in the aquarium industry of hobby. As the name implies, it is particularly more beneficial for plants rather than water alone.

You can use it to easily measure both temperature and pH value of soil and water conditions. It’s often used to ascertain the number of nutrients your soil needs to produce the right plant growth results.

The Bluelab pH Pen Pocket Tester is fully waterproofed and won’t suffer any damage when used as a pH reader for aquariums. This aquarium pH meter also lets you know when the battery is due for a change. It has a built-in automatic on/off feature, which usually helps to save battery for those who always forget to switch off their device after use.

Among other digital pH meters we’ve seen, the Bluelab pH tester has the best LCD display for a clear view of values and a backlight for easy reading. It has a hold-reading function which helps you to keep the information while you make notes.

You’ll love how easily the temperature measurement can be changed from ˚C to ˚F. The Bluelab aquarium pH pen meter also has a self-diagnosis function which lets you know when to recalibrate.

This is a very great feature, and it saves you time and calibration solutions too. However, during our tests, we found that this is not the fastest pH meter at displaying results values.

PROs
  • Auto on/off feature
  • Fully waterproof
  • LCD clear display
  • Designed to run with AAA batteries
CONs
  • Slow to display results

2. Apera pH Tester – Best pH Meter for Beginners

High Accuracy
Apera Instruments AI209 pH Tester Kit

This is a great starter pH Meter. This pH meter gives a great reading of +/- 0.1 pH value accuracy. It is battery powered, having a long-lasting runtime of about 2,000 hours.

It is a multipurpose pH tester used in measuring general water solutions having up to 3 points of auto-calibration.

This pH meter has a large dual-purpose LCD display which gives a clear accurate pH reading of 0-14 pH range, along with the temperature value of the medium, reading up to 50˚C temperature compensation. 

This top aquarium pH meter is temperature resistant and can give an accurate reading irrespective of the varying temperature, which is a must-have when looking out for a quick and accurate pH meter.

It has a smart-self diagnosis that warns of incorrect buffer solution and incorrect calibration. Good to know that it also comes in a fancy, portable carrying case.

However, we encountered some difficulty in calibration, requiring more than one try to get a correct calibration. It is quite costly when compared to other pH testers and quite fragile, so perhaps something you should take into consideration.

PROs
  • Designed with a high pH sensor
  • Equipped with a smart-self diagnosis
  • It has an auto-recognition of stable values which improves consistency and convenience
  • Built with a large dual-purpose LCD display
CONs
  • It is fragile and a bit expensive
  • It is a bit difficult in calibration

3. Dr.meter pH Meter with ATC

Dr.meter High Accuracy Pocket Size pH Meter with ATC

This is a great versatile pH meter for freshwater or saltwater aquariums used to measure the pH of different liquids with higher accuracy than most pH meters. 

It is built with an Automatic calibration and Automatic Temperature Compensation (ATC) which enables it to give an accurate pH reading at varying temperature levels.

It is manufactured with an instant response feature and a high-quality algorithm chip, making it an awesome choice for solution quality examination.

It comes with its own well designed package and offers a one year warranty. Although it’s a bit pricey, the high quality compensates completely for the price.

Sadly the temperature reading is displayed only in ˚C and cannot be changed to ˚F and it is a bit difficult to calibrate.

Also, there have been quite some reports of poor customer service from the manufacturing company.

PROs
  • Applicable to all types of liquids
  • A clear display of temperature and pH value
  • It is fast with high accuracy
  • Has a built-in Automatic Calibration and Automatic Temperature Compensation
CONs
  • The temperature reading cannot change from ˚C to ˚F
  • High reports of poor customer service

4. HM Digital pH Meter

HM Digital PH-200 Waterproof pH Meter, 0-14 pH Range, 0.01 pH Resolution, 0.02% Readout Accuracy

Having a sleek and slim design, the HM Digital pH/Temperature Meter is one of the handy dual-purpose tools used to measure the pH and temperature level of the aquarium water simultaneously.

It has a three pH calibration of 4, 7, and 10 pH levels, and measuring up to 50˚C temperature.

This pH meter for aquariums has a large LCD display to give a clear reading of the pH and temperature values. It is battery-powered and has an automatic power-off function, which saves you a lot of battery drainage.

It also has a button which helps you take notes of the pH and temperature measurement by holding the button for a few seconds.

This pH meter can also be used for hydroponics, gardening, brewery, boilers, and drinking water, among many others. Regards to the high quality of this handy tool, the relatively low price is extremely wonderful.

PROs
  • Can measure both pH and Temperature simultaneously
  • Has a three pH level calibration
  • Sleek, slim, and portable
  • Built-in Automatic Temperature Compensation Feature
CONs
  • Inadequate solution for calibration/testing

5. Apera Instruments pH Pen

Apera Instruments SX620 pH Pen Tester Kit

Remarkable for having a very high pH value accuracy of about 0.01, this tool is a general-purpose, complete testing tool as it comes with a 3 premixed calibration solutions, a portable case, and a pen tester. 

The Apera Instruments SX620 pH Pen Tester Kit has a very sleek and tiny design which makes it suitable to be used even for very small volume tests.

It has a replaceable probe, which makes it easy to replace the probe if it is broken or worn out, and has an automatic self-examination check to notify you when the probe is due for a change.

It features a one-button operation type to give a highly accurate pH and temperature reading. Also, the temperature reading can easily be changed from ˚C to ˚F. This pH meter has an automatic switch off function, which keeps it off when it has been idle for extended periods.

This Apera digital pH meter is highly sensitive and should be treated with severe care to avoid untimely damage. However, this pH meter is a bit pricey and is therefore not suitable for people who are on a low budget.
PROs
  • Highly accurate pH meter for aquarium
  • A portable case and 3 premixed calibration solution
  • Built-in Automatic Shut off function
  • Equipped with replaceable probe
CONs
  • Not ideal if you are on a low budget

6. KoolaMo Digital PH Meter – Best Cheap pH Meter

Best Cheap
KoolaMo Digital PH Meter with ATC

Sold at a fairly good price, the KoolaMo digital pH meter for aquariums is a great choice for first-time buyers.

It has a wide range of applications and can be used for Hydroponics, RO systems, aquarium, drinking water, pool, household use, or even simple laboratory analysis.

Equipped with a temperature measurement function, reading up to 80˚C, this pH meter can be also used as a standalone thermometer. It has a built-in Automatic Temperature Compensation which allows it to give accurate pH readings at varying temperatures of up to 80˚C.

This pH measurement device is battery powered and comes with its own battery. Following the instructions on the package, it is easy to calibrate. However it has a fragile and delicate glass probe which makes it not a good choice for long lasting, except it is handled with extreme care.

It provides an instant reading for both temperature and pH values and it is built with a sensitive electrode sensor to obtain accurate pH readings of 0-14 pH value, up to 0.01 pH accuracy, and a resolution of 0.01.

PROs
  • Comes with a carrying case
  • Easy to calibrate with a one-touch button
  • Can work as a standalone thermometer
  • Designed with Automatic Temperature Compensation
  • Built with a high sensitive electrode sensor to ensure accurate and precise pH readings
CONs
  • Fragile and delicate glass probe

7. Bluelab METCOM Combo Meter for pH

Bluelab METCOM Combo Meter for pH

This device is a 3in1 combo multipurpose tool for measuring, pH value, temperature, and conductivity. This saves a lot of money for buying other devices for running the separate tests.

It is more focused on plants than water and is essential for proper seed germination and plant growth, not just for aquarium water pH measurements.

The Bluelab METCOM Combo Meter has a large display which clearly shows an-easy-to-read values of the test readings. It is battery-powered and comes with its own battery. It also has a low power warning function which signals when the battery is low and needs to be replaced.

Equipped with a simple 2 point pH calibration function for improved accuracy, requires no calibration for conductivity and temperature measurement. It is built with a double-junction probe for superior accuracy. However, the  probe is very sensitive and should be treated with severe care to avoid any damage.

Sadly this product is not a good choice for a tight budget, unless it is handled with utmost care, then the longevity can be compensated for.

PROs
  • Has customizable measurement scales for extra convenience
  • Can easily change temperature setting from ˚C to ˚F
  • 3in1 combo functions for measuring pH, conductivity, and temperature
  • Comes with its own battery
  • Double-junction probe for high accuracy
CONs
  • Not a good option for a tight budget
  • The probe is delicate and prone to damage

8. Apera Instruments Lab pH Meter – Best Tech pH Meter

8
Apera Instruments Benchtop Lab pH Meter

This is just the perfect choice not only as an aquarium pH meter but also as a pH meter for full different agricultural and laboratory tasks. 

It supports amazing functions, which include pH electrode, temperature measurement, and automatic temperature compensation which enables it to measure both temperature and pH value, giving accurate and precise pH values ranging from 0 to 14, and temperature reading in varying temperature medium ranging from 0 to 100˚C.

Apera Instruments pH meters have an advanced calibration function, that helps you set the calibration yourself, which is so easy to do using the 1-3 points of automatic calibration as provided in the instructions manual as well.

It comes equipped with a variety of calibrations already prepared, which offers you a wide range of options to choose from. It has an amazing large backlit LCD display quality which gives an easy to read result of temperature and pH values simultaneously along with stabilization and calibration icons which shows up immediately and is almost stable at the first test.

It is designed with an electrode holder which is not a hassle to install and use. Electrically powered, it thus requires the minimum electricity voltage as most gadgets. Please note that it should not be used in a short circuit or low/high voltage and/or current supply.

From a well known manufacturer, this pH tester comes with a 2 years warranty for the meter and a 6 months warranty for the electrode.

PROs
  • It is easy to use
  • Self-diagnosis function
  • Advanced Automatic calibration mode along with a calibration guide
  • Built-in advanced digital processing technology for quick and stable readings
  • Equipped with an easy-to-install electrode holder with an already prepared calibration solution
CONs
  • Unable to connect the vertical holder to the main unit
  • Comes with a rather high price tag

9. VIVOSUN 4-in-1 Digital pH Meter

VIVOSUN 4-in-1 Digital pH Meter with ATC

As the name implies, the VIVOSUN pH meter combines four main functions, so one can you can accurately measure PH, TDS, EC, and temperature values.

It is just an ideal pH meter for marine aquariums, but also freshwater and gardening activities, both indoors and outdoors.

The lock function can be extremely handy while taking measurements, as you can simply read and record, while the VIVOSUN pH meter will lock the reading result.

Last but not least, it has a lovely attractive display that’s green backlit, ensuring you can easily read the measuring results in any condition.

PROs
  • Suitable for four functions: pH, TDS, EC, and Temp
  • Very portable and easy to use
  • Can test soil runoff water with this meter
  • Very affordable with high quality
CONs
  • pH meter designed only for liquids

Frequently asked questions

How often to check the pH in an aquarium?

The aquarium water pH should be tested on a monthly basis, preferably every two weeks, to allow for the detection of any fluctuations before they can become an issue. For instance, it could be that you tried a new substrate that can influence the pH levels, so it’s important to frequently have the pH tested.

What raises the aquarium water pH?

The main reason can be an ammonia spike. That’s why regular water changes are recommended in order to get rid of fish waste and leftover food from the aquarium.

What is the best pH level for aquarium water?

7.0 is considered a neutral pH value. Most freshwater aquarium tropical fish thrive in the water of pH levels between 6.5 to 7.5, although it’s important to check carefully each species for specific higher or lower pH levels needed. The aquarium water pH has the tendency to drop in time due to the breakdown of organic material, and the key to deal with this is simply to do regular water changes, most likely on a weekly basis.

To conclude

The usefulness of having one the best pH meter for an aquarium is irreplaceable as this simple accessory will help you a great deal to maintain the perfect environment for the fish, plants and corals.

This ensures that the aquarium inhabitants live in a safe environment at all times which will not impede their well being and health.

From our reviews, judging by its features, capabilities, price, and the feedback from many people, the KoolaMo Digital PH Meter would be just a great overall pH meter for any kind of aquarium water testing. This is because it has the most needed component like Automatic Temperature Compensation (ATC) to provide accurate pH test results of the aquarium water, and also comes with an attractive price tag.

This makes sure that your aquarium fish and other inhabitants have the right water pH requirements for proper growth and overall health.