The Best pH Meter for Aquariums

TheCritterCove is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. See more here.

best ph meter for aquarium

The pH of an aquarium is one of the most important factors to be considered in ensuring a healthy home for your pet fish.

Some fish species have little tolerance for changes in water pH and so it is important that you monitor this regularly with the best pH meter for an aquarium to have a healthy and happy pet.

pH is the measure of the hydrogen ion concentration in your water or simply put, how acidic or basic your water is.

A pH meter is graduated on a scale of 0 to 14, with 0 being the most acidic and 14 being the most basic, 7 is neutral.

Since pH is affected by activities in the water and the source of the water, it is good practice to monitor this as most fish can survive within the range of 6 and 8.

Different fish species are tolerant of different pH levels so before you bring a new fish home, you have to gather as much information about it including the best pH for it so you can provide it with a home in which it will survive and stay healthy.   

At higher pH values, the percentage of toxic ammonia in the water increases. The excretion of ammonia by fish is also inhibited at high pH levels, preventing excretion.

This causes stress to your fish and exposes them to diseases and infection. Monitoring and maintaining the pH of your aquarium within healthy limits can help you free your fish from unnecessary stress and helps with being resistant to disease.

It can also help to improve growth, behavior, and general appearance.

We Recommend

After seeing numerous pH meters, we have a pretty solid idea of what characteristics make the best pH meter for aquariums, and the Apera Instruments Value Series pH20 Tester Kit it’s our top choice.

  • Easy with auto-calibration and buffer recognition
  • High response rate
  • Powered by AAA batteries

Advantages of using a pH Meter

There are various devices that can be used to test the pH of your aquarium, but the use of a pH meter is better and gives you a more definitive result.

  • A pH meter once calibrated will give you a straightforward reading which is easily understood. It reduces the risk and occurrences of mistakes in the reading.
  • Results obtained from the use of a pH meter are not objective but factual. When compared to a testing strip that uses colors, the result is based on how you see the color. But with a meter, you get a numerical result.
  • It is more convenient and economical in the long run to use pH meters instead of some other measuring devices that are single use only. Meters can be used several times so you get to save money.

How to Use a pH Meter

After you have decided on which pH meter you want to use, it is time to learn how to use it so you can get the best results each time.

Sometimes we don’t get the best results from products not because the products are defective but because of wrong usage.

Different pH meters have their specific directions for use and so the best thing to do is to follow the instructions, but generally, here are the steps to properly use a pH meter:

The first thing to do is calibrate the meter. Collect your solutions of different known pH levels and the electrode probe. Clean the probe with deionized water and dry it with a tissue.

  • Dip the probe in a solution of pH 7 and allow it to become stable. Then program the meter to read 7.
  • Dry the probe and then dip into a buffer solution with a pH of 2. Allow it to stabilize and set the meter to 2. This will be registered and recognized when used again.
  • When you are ready to use your pH meter, put it on and give it a few minutes to get ready for use. Make sure that it is in pH mode (for meters that have more than one mode) before you use it.
  • Dip the electrode probe into the solution you want to test and allow it to stay there for a while so you can get accurate readings.
  • Once it is stabilized, take the reading that is on the display.
  • Rinse the electrode probe and put it back in your storage solution.

Calibrating A pH Meter without Buffering Solution

If you don’t have any buffering solution from the store with which to calibrate your new pH meter, you can make use of common products from the kitchen.

You will need a calibrated pH meter to make your calibrating solutions and even though it won’t be as accurate as the ones you purchase, it’s very close.

  • Add tap water to a container, filling it up to 80%
  • Add 10 grams of monopotassium phosphate (MKP) slowly and stir until it dissolves
  • Slowly add potassium hydroxide to the solution and keep stirring. Use the already calibrated meter to test the solution as you add until it gives a pH reading of 7
  • To make a buffer for pH 4, fill another container up to 80% and add 20 grams of citric acid
  • Then add KOH and measure until the pH meter reads 4
  • Allow both buffers to be undisturbed for some hours before use

The Best pH Meter for Aquarium

1. Apera Instruments Value Series pH20 Tester Kit

First on our list of best pH meter for aquarium is the Apera Instruments Value Series pH20 Tester Kit.

It is also the best on the list for hydroponics and has stood up to its name for accurate readings only.

You can use it conveniently as it is powered by batteries, allowing you long-lasting usage of up to 2,000 hours.

It has up to 3 points of auto-calibration and a range of 0 to 500C auto temperature compensation to ensure accurate readings even in environments with fluctuating temperatures.

The auto-recognition and auto indication of stable readings features takes away the trouble of guessing when to manually hold measurement. 

Each case comes with calibrating solutions that allow you up to 15 calibrations, so you can do a lot of work with this meter before worrying about the further purchase of calibrating solutions.

You get a dual display of temperature and pH value on the screen, and also indicators of the 3 points of calibrations.

Other features are a self-diagnosis that runs and indicates when your device is faulty to save you the error of wrong readings.

You receive out of range measurement warnings and warnings on incorrect calibration, all to ensure that your results are accurate at all times. Being waterproof and dustproof, it is durable and built to be long-lasting.


  • Has an auto-calibration feature and buffer recognition that allows you calibrate easily
  • Has an auto temperature compensation that serves to give you accurate readings irrespective of temperature fluctuation
  • High response rate
  • Auto-recognition of stable values saving you the stress of manually holding measurement
  • Comes with a lanyard and buffers for calibration
  • Its batteries give you up to 2000 hours of continuous usage


  • You may need to recalibrate frequently to maintain accurate readings

2. Dr. Meter PH100-V 0.01 Pocket Size pH Meter

Dr. Meter PH100-V 0.01 Pocket Size pH Meter is a device that makes taking care of your fish easier.

You can now easily calibrate your meter and monitor the pH of your aquarium as this device does it with just the push of a button.

The 3 point calibration automatically identifies the calibration liquid and you can get a pH reading instantaneously.

The whole process is easy and convenient from calibration to getting pH readings and you do not need any special skill or experience to work with this device.

A sudden change or inconsistency in the temperature of the water in your aquarium can cause the pH reading to be off.

This is taken into consideration during manufacture and so with the automatic temperature compensation, possible inaccuracies that could arise from temperature change can be prevented and what you get at all times will be accurate readings.

It is suitable for a variety of uses apart from the pH of your aquaria like testing drinking water, swimming pool, spa, and hydroponics.


  • Easy to use
  • Easy to calibrate
  • Has automatic temperature compensation feature
  • Gives accurate readings
  • Has a variety of applications


  • Small display and symbols are sometimes difficult to read

3. Bluelab Mongua Guardian Monitor For pH

This Bluelab pH meter allows you to monitor your aquarium chemical levels all round the clock.

With power from the mains, you power this device and get accurate readings by placing the probes into the aquarium.

The display is large and easy to read so you can read your results without stress, making it easy to work with no matter your age.

Calibrating it is as easy as using it as you can get it done just by the push of a button.

To ensure the health of your fish and the water in their aquarium, this device comes with an alarm that calls your attention to immediately correct the dangerous rise or fall in chemical levels.

The temperature compensation ensures that you get accurate readings irrespective of the water temperature, so you are rest assured that no matter the condition, your results will always be accurate.

There are a few devices that help you maintain the perfect environment for your fish in its aquarium and this is one.


  • Large and easy to read display
  • Easily calibrated pH meter
  • Flashing alarms
  • Has temperature compensation


  • The probe can easily get damaged

4. Vantakool Digital pH Meter

An alluring feature of the Plantz Shoppe Digital pH Meter is its size. It allows you to conveniently test the hydrogen ion concentration of your aquarium anytime you want.

Apart from its use in ensuring the healthy state of your aquarium, it is also great for testing drinking water.

You have a large display that gives you easy to see readings, ensuring you have a great user experience.

You can calibrate easily and get accurate readings that are far better than the use of test strips and color charts.

The need to calibrate often is being made easy because of the auto calibration feature, so you have no reason to get readings that are anything less than accurate.

With a wide range of 0 to 14, you can use this device for pH testing of any kind.


  • Has an auto-calibration feature that makes calibration easy and ensures accurate readings
  • It has a very portable size making its use very convenient
  • Large and easy to read display
  • The package comes with buffers and a carrying case


  • Distilled water has to be used for calibration and as this is not always available at home, you may need to go to the store

5. Cakie Digital pH Meter

And we will be rounding up the list of best pH meters for aquariums with this Cakie Digital pH Meter.

It is great for you even if you have no experience using meters and is very affordable.

As a pH meter and a thermometer, it will come in handy in the care of your fish and in keeping your aquarium healthy.

Calibrating this device is very easy and is done with a single touch. You don’t need any experience to do this and you get instant pH readings.

Apart from its use in testing the aquarium, it can also be used to test for pools, food, hydroponics, wine, beer, and a lot more.


  • Has a wide variety of applications
  • Is easily calibrated
  • Provides readings immediately
  • Comes at a very cheap price


  • It is a fragile device and needs care when handling

Things To Look Out For When Buying a Good pH Meter for Aquarium

There are a lot of pH meters in the market and making the choice that is best for you can become confusing.

This buying guide will help you make the best choice even in the midst of so many products being thrown at your face as you will know the important factors to consider before making a purchase.


No one wants to constantly go back to the store for a new meter. Not only is it wasteful, but it is also inconvenient.

So when looking for a pH meter check that is durable and can withstand multiple usage and handling.

Choose a meter that won’t break when exposed to chemicals, water, or dirt.

Automatic Temperature Compensation

The pH readings are influenced by temperature changes and if you make use of a meter without the temperature compensation feature, your readings will not be as accurate.

To ensure that you always get the right readings, check that your meter has automatic temperature compensation.

This is especially important if your meter won’t be used for the aquarium only but to check for the pH of samples at high temperatures.

Accuracy and Consistency

The whole point of using a pH meter is to be able to properly monitor and help you maintain the pH of your aquarium for the good health of your fish.

This means the meter you use must be accurate if not your fish will suffer and you won’t even know it.

Accuracy is a must and so is consistency. Your meter should always give the same reading when tested with the same substance.

Ease of Use

A pH meter that is easy to calibrate and use will go a long way in saving you from stress each time you want to make use of it.

Go for a meter that is easy to calibrate and requires no experience to operate.


You have a lot of options to choose from but it all comes down to your budget. If you are on a tight budget, there is no need to worry as you can still get something good.

There are meters which are simple and cost less but still gets the job done.

Commonly Asked Questions About pH Meters

Q: How Often Should I Calibrate My pH Meter?

It is strongly recommended that pH meters be calibrated before every use for the most accurate results. If that is not achievable, at least once a month will do fine.

Q: Do pH Meters Need to Be Calibrated?

It is necessary to calibrate pH meters because of the changes associated with the electrode over time.

Regular calibration adjusts the electrode and clears the changes that could affect your result ensuring that your readings are accurate at all times.

Q: What Do I Do If My pH Probe Dries Out?

A dried pH probe will often lead to slow response and incorrect readings. To revive a dried out probe, submerge the bulb and junction in pH storage solution for at least an hour and then calibrate before use.

Q: Does Buffer Solution Go Bad?

Yes, they do and the time it takes for this to happen depends on the buffer. A buffer with pH 7 will expire after 2 years of being opened, while a buffer with pH 4 will be good for as long as 4 years.


With this list, your confusion on the best pH meter for your aquarium has undoubtedly been taken care of.

Now you have fewer products to choose from and you have tips to help you in making the best choice.

If you are still confused about the best choice to make, may we suggest that you pick Apera Instruments Value Series pH20 Tester Kit.

It gives fast and accurate readings with automatic temperature compensation. You can also calibrate it easily and use it conveniently due to the long-lasting battery.

Another product you can choose is Dr. Meter PH100-V 0.01 Pocket Size pH Meter. It is very easy to use and calibrate and you are sure of accurate readings each time.

Whatever your choice is from these reviewed products, you can be sure that your aquarium and fish are in good hands.