Apex PH Probe Won’t Calibrate: Reasons and Solutions

When a ph probe won’t calibrate correctly, it can be a hassle for us. Like, we can face problems in any lab work. Apex ph probe is a good one but it may also show some issues. Like calibrating issues.

So, we must know why the Apex ph probe won’t calibrate.

If the apex ph probe is too much older or broken or has a dirty junction on the glass electrode it may not calibrate. For calibration, we need to use buffer solutions. Calibrating with buffer solutions keeps the probe good in condition for a long time. You can calibrate the apex ph probe manually too.

Now it is important to know the reasons for apex ph not calibrating in detail. After knowing the reasons we will solve the issues according to the problem base.

Why Does Apex PH Probe Won’t Calibrate: Reasons and Solutions

Apex PH Probe

Knowing the right conditions of the water in your aquarium is important. As acidic or alkaline water is not good for the health of the fish. The fish can even die in the lack of a proper environment in the aquarium.

 So, when our apex ph probe is not calibrating, knowing the reasons is a must. As there are various reasons for not calibrating the apex ph probe.

If you are an aquarist, knowing the pH level of the water in the aquarium is a must. You may know the PH level of the aquarium should be between 6.8 to 7.8. Between 6.8 to 7.8, the PH is kind of neutral. Not much acidic or alkaline.

So, if you own an apex PH meter, the meter has to be calibrated right. Otherwise, the fish may die.

There are various reasons for not calibrating the apex meter. They can be faulty or dirty electrodes. Sometimes, temperatures are also an issue for not calibrating the apex ph meter.

And many more reasons. Without knowing the reasons, how can we go to the solutions? So, let’s know about the exact issue the apex PH probe is facing for not calibrating. So, let’s get into solutions according to the problems.

Reason 1: The Apex PH Meter is Not Calibrated in Buffer Solutions For a Long Time

After 2- 3 months, it is important to calibrate your Apex PH meter in the buffer solutions. If you do not calibrate it frequently, the electrodes start to be stable in one value. So, the apex PH meter won’t calibrate.

So, if the apex PH meter hasn’t gone through the calibration process for a long time, calibrate it. 


When buying the apex PH meter, you may find two solution packets with it. Those are also known as apex ph probe calibration solutions. Check those solutions. One packet is written 7, another is 10.

These buffer solutions are needed to calibrate the apex PH meter.

So, how to calibrate the apex ph probe? Here are the steps

  • First of all, we need to log into our Apex account or Apex fusion or Apex local dashboard. After logging in, find the configuration button. And click it.
  • In the configuration page, there is an input button. Click it. Here is an option written PH. After going to the ph option, we will click the ph probe configuration option. Then we will find the automatic probe calibration button. Clicking this starts the calibration methods. Tap the continue icon.
  • Now time to calibrate the probe in the lower range first. Now, take the buffer solution packet written 7. Remove the cap of the probe. And insert it into the packet. And click the ‘next’ icon in the apex account. In the indicator, we will get to know if the ph meter is counting right. If there are any difficulties in taking readings, then shake the probes in the buffer solution.
  • If the lower buffer calibration is done, we need to step into the buffer solution 10. Before placing the probes into the packet, rinse them. After rinsing insert the probes into the high-range buffer solution packet. And tap the next button. Wait sometimes as you have done when calibrating at Ph 7.
  • If the calibration is done, the apex account will notify when clicking the ‘NEXT’ icon. If it is done, attach the probe holder. And submerge the probe in the water. And check the ph level in the apex account. Also if needed, select your preferable Ph level to notify you.

This is how easily anyone can calibrate the apex ph meter on their own. Calibrating the apex ph meter fixes 80% of problems.

Reason 2: Dirty PH Probes

Dirty PH Probes Cleaning

Dirty ph probes are the hindrances to getting the right read of the apex ph meter.

So, cleaning the probes once every two weeks is needed. If it becomes a hassle for you then you must clean the probes at least once a month. If you haven’t cleared the dirt for a long time, this can be a reason for not calibrating the apex ph meter.


Clean the probe or glass electrodes once a month. For better performance clean the apex ph probes twice a month.

To clean or rinse the probes never use distilled water.

To clean the probes DI water can be used.

Also, chemical wipes can be used.

Warm tap water and vinegar water (5%) can also be used to clean the probes. These will unclog the junctions to read the level of PH correctly.

Reason 3: Dry Probes

If the apex ph probes are dried out then they cause calibration problems. As long as the probes are wet they determine their good conditions.


If the apex ph probe dried out then it needed to rehydrate.

To rehydrate we can use a KCl solution. Soak the dirt or contamination-free ph probe in KCl solution for 24 hours.

This will rehydrate the dried apex ph probe.

Reason 4: Ages of the Apex PH probes or Physical Damage

Usually, the probe’s lifespan is between 12-18 months. If the probes of the apex ph meter are too old then they may face problems in calibrating.

Also, check if there are any physical damages in the body of the apex probes. If yes, then these are affecting the Ph meter for not calibrating.


If the PH meter probes are too much older or have damage in the body then it is better to replace the probes.

The apex pH probe color is blue. So, before replacing it, buy the right one.

Reason 5: Temperature Issues with the Apex PH Meter

If the temperature sensor is not working perfectly then the apex PH probe will not read the right PH level. Because the level of PH depends on the temperatures also.

So if everything is okay with the apex meter probe, it is time to check the temperature sensors.


If the temperature sensors are not working then replacing them is the best solution.

So, replace them and know the right pH level of the water in your aquarium.

Usually, these issues are the reason for not calibrating rightly in the apex PH meter.


How Often Should Apex PH Probe Be Calibrated?

Apex probe should be calibrated within 2-3 months. Regular calibration is important to keep the apex PH probe good in condition for a long time. It requires 2-3 dollars for calibrating the ph probes once.

Can You Clean The PH Probe With Vinegar?

Yes, the probes can be cleaned with vinegar. But, not in direct vinegar. You need to mix the vinegar with water. Use 5% of vinegar and submerge the probes for 24 hours. It will clean the dirt from the probes.

What Should I Do If The Probes Are Dried Out?

If the probes are dried out then you need to rehydrate them. To rehydrate use KCL solutions. Dry probes indicate the bad conditions of a PH meter.


Now you know why the apex ph probe won’t calibrate. After knowing the reasons you can go to the solution part.

You know now, how calibration helps the apex ph meter, and also know other solutions. So, know the right ph level of your aquarium or any lab work. And Create a good environment for your fish.

Howard Parker

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