Ph electrode refilling

[Cory]

I have a double junction lab grade ph probe that came with my Apex. Is it possible to drill a small hole and refil the electrolyte, provided i can cap the hole afterwards?

 

[MnFish1]

I have a double junction lab grade ph probe that came with my Apex. Is it possible to drill a small hole and refil the electrolyte, provided i can cap the hole afterwards?

I would not. I would buy a new probe. First - you would have to have an extremely well calibrated buffer to put back inside it. Second there is no guarantee that you can drill the hole, fill it with the 'right' amount, and cap it. Third - by the time you've done all of that 'stuff' - you may have spent more time and money than just buying a new one.

But - just out of curiousity - what is the reason you're wanting to do this in the first place?

 

[Cory]

I would not. I would buy a new probe. First - you would have to have an extremely well calibrated buffer to put back inside it. Second there is no guarantee that you can drill the hole, fill it with the 'right' amount, and cap it. Third - by the time you've done all of that 'stuff' - you may have spent more time and money than just buying a new one.

But - just out of curiousity - what is the reason you're wanting to do this in the first place?

Its my understanding that most use silver chloride solution that you can buy so i wasn't aware of having to need an extremely well calibrated buffer. Also I read that ph probes need to be calibrated because every new probe has a slightly different voltage, so calibration fixes this. Thus any change in voltage or electrolyte difference is fixed via calibration. Or do i got the wrong idea? Really I dont know. This is why I thought it could be done. Why am i doing it? Well, in Canada the ph probe for the Apex is around 125$. Right now its 101 for black friday sales. However if I could just refil it for 25$ then thats a significant savings.

 

[Randy Holmes-Farley Verified Community Expert]

The fill solution should be standard and easy to buy. Why do you think refilling is necessary or useful in this case?

 

[Cory]

The fill solution should be standard and easy to buy. Why do you think refilling is necessary or useful in this case?

I thought when they get old its the solution that gets old, not the probe itself.

 

[Randy Holmes-Farley Verified Community Expert]

I thought when they get old the solution that gets old, not the probe itself.

I think the glass often gets messed up.

How should I clean a pH electrode, or revive a damaged electrode? - The Laboratory People

Traditional glass pH electrodes are very delicate and need regular care to keep them in good working order. If your...

camblab.info

 

[Cory]

I think the glass often gets messed up.

How should I clean a pH electrode, or revive a damaged electrode? - The Laboratory People

Traditional glass pH electrodes are very delicate and need regular care to keep them in good working order. If your...

camblab.info

What happens to the glass? Is it a microscopic thing or a seal breaks? Something else?

 

[Randy Holmes-Farley Verified Community Expert]

What happens to the glass? Is it a microscopic thing or a seal breaks? Something else?

It needs to be permeable, and it gets clogged up.

 

[Cory]

It needs to be permeable, and it gets clogged up.

How about soaking in hcl and then sodium hydroxide? Thats cheap enough. Or maybe bleach, hcl, then sodium hydroxide?

 

[Randy Holmes-Farley Verified Community Expert]

How about soaking in hcl and then sodium hydroxide? Thats cheap enough. Or maybe bleach, hcl, then sodium hydroxide?

I would soak it in diluted HCL (1 part muriatic acid in 10 parts fresh water) overnight, rinse well, then soak in seawater for an hour, rinse, then see if you can calibrate it. Leave it in each calibration solution extra long (5+ min) to allow equilibration.

 

[Dan_P]

I have a double junction lab grade ph probe that came with my Apex. Is it possible to drill a small hole and refil the electrolyte, provided i can cap the hole afterwards?

I think the Apex vendor, by not putting a refill cap, is telling you that your probe never needs to be refilled and/or that it is not a long-life piece of equipment so don’t worry about maintenance. When you cannot recalibrate it or response time is slow, replace it.

 

[Cory]

I think the Apex vendor, by not putting a refill cap, is telling you that your probe never needs to be refilled and/or that it is not a long-life piece of equipment so don’t worry about maintenance. When you cannot recalibrate it or response time is slow, replace it.

Thanks, Dan. How long do you get out of yours?

 

[Dan_P]

Thanks, Dan. How long do you get out of yours?

I don’t have data for you because my probe is not constantly in aquarium water. I do not constantly monitor pH. Here is my expectation. Unless you are religiously and regularly removing the biofilm, pH electrodes may only last 1-2 years, maybe a bit longer if you are not interested in high accuracy.

 

[YOYOYOReefer]

milwaukee ma917 probes are refillable. they cost about 3-4 times what a normal probe costs..
i would not suggest use of silver chloride in an aquarium these use 3.5 molar KCL works for ORP as well. Less chance of any electolyte polluting the reef.

I have found even with changing electrolyte religiously the electrode will eventually fail but changing the fluid makes it last longer.. we use lots of ph probes at my office.

 

[Cory]

milwaukee ma917 probes are refillable. they cost about 3-4 times what a normal probe costs..
i would not suggest use of silver chloride in an aquarium these use 3.5 molar KCL works for ORP as well. Less chance of any electolyte polluting the reef.

I have found even with changing electrolyte religiously the electrode will eventually fail but changing the fluid makes it last longer.. we use lots of ph probes at my office.

Whats the difference between the fluid and electrolyte?

 

[Malcontent]

I wonder if it's a gel filled probe though--that would certainly make this question moot.

 

[Randy Holmes-Farley Verified Community Expert]

Whats the difference between the fluid and electrolyte?

None, really.

 

[YOYOYOReefer]

Whats the difference between the fluid and electrolyte?

same thing just my bad grammer, english is not my first language.