pH testing

[Joel Armstrong]

Hi,

I'd like to ask if anyone has experience with Milwaukee pH testers?

I understand good quality pH meters are most likely more accurate, however I've got a Milwaukee pH56 pro, and curious if anyone has any experience with this particular pH pen?



#pH

 

[Joel Armstrong]

Crickets chirping

Tumbleweed rolling

 

[Immortal1]

All are crickets are in hibernation for the winter LOL
I personally have not used that ph pen. I have, and still am using Milwaukee MC122 pH controllers.
If the pH pen is build at least as well as the controller, then I would assume it is pretty decent.
Biggest thing would be learning the procedure for calibrating the pen.
With the controller probe, you have 2 different calibration fluids - 7pH and 4 or 10pH.

 

[BigWave]

I agree with Immortall, Milwaukee is a great company and products so their pH pen is probably on that level. I do know for a good pen look at how its calibrated. Generally good ones are also stored in some kind of solution. I bought a crappy cheap chinese one and it went in the trash.

 

[GreggZ]

I know several people who use this model and are very happy with it.

It's kind of a hybrid in between a cheap pH pen and a pH monitor or controller.

The key is that it is a double junction probe, and the probe is replaceable. So it's a much higher quality than the cheap pens and should last a LOT longer.

The one thing to be aware of is that you have to store it in solution and not let it dry out. That is why I prefer a pH monitor as it's always in tank and always wet.

But in general that unit is MUCH better than the common pH pens, which are pretty much disposable and need to be replaced very often. A good in between for a lot of people.

 

[Joel Armstrong]

All are crickets are in hibernation for the winter LOL
I personally have not used that ph pen. I have, and still am using Milwaukee MC122 pH controllers.
If the pH pen is build at least as well as the controller, then I would assume it is pretty decent.
Biggest thing would be learning the procedure for calibrating the pen.
With the controller probe, you have 2 different calibration fluids - 7pH and 4 or 10pH.

Hi,

I'm in Australia, it's summer, crickets are everywhere, no tumbleweed where I am though LOL

I've learned how to calibrate the pen, it's two point calibration with 4.01 and 7.01 calibration fluids, the process is quite simple really.

I've read a lot of comments from Gregg Zydeck about cheap pH pens being unreliable, and I was not sure if my pH pen fell into that category.

Thanks for your comments

 

[Joel Armstrong]

I know several people who use this model and are very happy with it.

It's kind of a hybrid in between a cheap pH pen and a pH monitor or controller.

The key is that it is a double junction probe, and the probe is replaceable. So it's a much higher quality than the cheap pens and should last a LOT longer.

The one thing to be aware of is that you have to store it in solution and not let it dry out. That is why I prefer a pH monitor as it's always in tank and always wet.

But in general that unit is MUCH better than the common pH pens, which are pretty much disposable and need to be replaced very often. A good in between for a lot of people.

Thanks Gregg,

I've only recently started to use the pH pen, I've calibrated it a couple times, and I do store it in the storage solution.

I've taken a few samples of tank water to test over the course of a few weeks. I've let samples sit. I've tested the samples after 4 days and the pen reads the sample at 7.68 - 7.71
I've then tested the same sample at 6 days, and 7 days and the pen reads the sample at 7.90 - 7.93
Is it possible the sample can take up to a week to fully degas?

According to the pen, i was dropping the pH of the tank to 5.7
I've reduced the co2 a little, and dropping the pH of the tank to 6.2 by the time lights come on, eventually dropping a little further to 6.15
I suspect I'm still injecting too much co2.

 

[Joel Armstrong]

I agree with Immortall, Milwaukee is a great company and products so their pH pen is probably on that level. I do know for a good pen look at how its calibrated. Generally good ones are also stored in some kind of solution. I bought a crappy cheap chinese one and it went in the trash.

Thanks Steve,

I did think Milwaukee was a good brand, and I researched a little before purchasing it. Wasn't real sure how it stacked up against other pens/meters though.

Cheers

 

[GreggZ]

Thanks Gregg,

I've only recently started to use the pH pen, I've calibrated it a couple times, and I do store it in the storage solution.

I've taken a few samples of tank water to test over the course of a few weeks. I've let samples sit. I've tested the samples after 4 days and the pen reads the sample at 7.68 - 7.71
I've then tested the same sample at 6 days, and 7 days and the pen reads the sample at 7.90 - 7.93
Is it possible the sample can take up to a week to fully degas?

According to the pen, i was dropping the pH of the tank to 5.7
I've reduced the co2 a little, and dropping the pH of the tank to 6.2 by the time lights come on, eventually dropping a little further to 6.15
I suspect I'm still injecting too much co2.

Interesting. I usually see samples completely degassed in about 3 days or so. If you go beyond 7 days does it change further? Do you know the dKH of the source water? That should also provide a clue.

But in any event yes based in what you are saying you are providing way more CO2 than is needed. Like most things there is a law of diminishing returns. And at some point could even be detrimental. At least I have heard a few people say that but have never tested the theory in my own tank.

I take it you don't have any livestock in the tank yet??

 

[Joel Armstrong]

Interesting. I usually see samples completely degassed in about 3 days or so. If you go beyond 7 days does it change further? Do you know the dKH of the source water? That should also provide a clue.

But in any event yes based in what you are saying you are providing way more CO2 than is needed. Like most things there is a law of diminishing returns. And at some point could even be detrimental. At least I have heard a few people say that but have never tested the theory in my own tank.

I take it you don't have any livestock in the tank yet??

Hi Gregg,

I've tested the sample beyond 7 days, yes. Constantly reads 7.9 pH

I'm currently using tap water, a salifert KH test is indicating 3dKH. The 3rd drop turns the test water from blue to a pale yellow.

I do have neon tetras and shrimp in the tank.

Thanks for your help here, greatly appreciated.

 

[GreggZ]

Hi Gregg,

I've tested the sample beyond 7 days, yes. Constantly reads 7.9 pH

I'm currently using tap water, a salifert KH test is indicating 3dKH. The 3rd drop turns the test water from blue to a pale yellow.

I do have neon tetras and shrimp in the tank.

Thanks for your help here, greatly appreciated.

OK now it's even more interesting.

At 3 dKH I would expect your fully degassed would be about 7.4 or so at full equilibrium with the atmosphere.

Are you testing the tap water or water from the tank? If from the tank is there anything in the tank that could be raising/lowering dKH? What is the substrate?

If you are testing the tap are you testing it directly from the tap as well as after aging?

Typically if tap water pH rises after aging the tap water contains dissolved CO2, which is pretty common.

And typically if tap water pH lowers after aging the municipality is using something like sodium hydroxide to raise the pH temporarily.

You've got a puzzle there and I like a good mystery. And while I know you are on the other side of the world I have to assume the laws of science apply there too. So I am not sure what is going on yet but there has to be some explanation. Hmmmmm.....gotta think this one over.

 

[Joel Armstrong]

OK now it's even more interesting.

At 3 dKH I would expect your fully degassed would be about 7.4 or so at full equilibrium with the atmosphere.

Are you testing the tap water or water from the tank? If from the tank is there anything in the tank that could be raising/lowering dKH? What is the substrate?

If you are testing the tap are you testing it directly from the tap as well as after aging?

Typically if tap water pH rises after aging the tap water contains dissolved CO2, which is pretty common.

And typically if tap water pH lowers after aging the municipality is using something like sodium hydroxide to raise the pH temporarily.

You've got a puzzle there and I like a good mystery. And while I know you are on the other side of the world I have to assume the laws of science apply there too. So I am not sure what is going on yet but there has to be some explanation. Hmmmmm.....gotta think this one over.

Tested again with new water samples.

Tap water straight from the tap, pH =7.8

Testing KH with salifert freshwater test. I'd much prefer an accurate number as opposed to 'shades of grey'

Tap water aged 3 days,
pH =7.8
dKH = 3

Tank water aged 3 days
pH =7.43
dKH =2

I have ADA Amazonia new version II soil. 7 months old

Tank peaks at pH 6.15 from CO2 injection

Laws of science don't apply in Australia, didn't you know?

 

[Joel Armstrong]

I'm yet to set-up and install my RO system, so I'm not overly concerned about my tap water, it's more of a learning exercise, and an effort to optimise CO2.

 

[Art]

Joel -

I don't know about this pH pen but my experience tells me to always be extra careful with pH measurements as they can be off, sometimes by a lot. I always recommend the following schedule.

1. Calibrate probe - keep the 4 and 7 test packets sealed from air.
2. Test the 4 and 7 pH packets every week.
3. If pH is off on the packet tests, then calibrate. If not, leave for another week.
4. Change packets after 1 month.

Measurement drift is a real thing with these probes, some more than others. The above will allow you to get to know your pH pen and how often you need to calibrate it to keep it on target. At the very least, it will give you confidence in your measurements.

 

[GreggZ]

Tap water aged 3 days,
pH =7.8
dKH = 3

Tank water aged 3 days
pH =7.43
dKH =2

I have ADA Amazonia new version II soil. 7 months old

Joel I'd buy those numbers. Keep in mind when measuring dKh that we are only dealing in whole numbers. So what you read as "2" might be 1.6 or 2.5. Just saying it's not an exact science with our methods.

And makes sense the dKH drops a bit from the Amazonia. That's why it's difficult to use a pH controller with active soil. The dKH is a moving target. In that case better to control with the flow of CO2 and keep it constant.

That's one of the reasons I stopped adding carbonates. I felt I was fighting the soil, and I prefer to use a pH controller.

Hope that makes sense.

 

[Joel Armstrong]

Joel I'd buy those numbers. Keep in mind when measuring dKh that we are only dealing in whole numbers. So what you read as "2" might be 1.6 or 2.5. Just saying it's not an exact science with our methods.

And makes sense the dKH drops a bit from the Amazonia. That's why it's difficult to use a pH controller with active soil. The dKH is a moving target. In that case better to control with the flow of CO2 and keep it constant.

That's one of the reasons I stopped adding carbonates. I felt I was fighting the soil, and I prefer to use a pH controller.

Hope that makes sense.

Thanks Gregg,

What you said makes perfect sense.

Thanks for your responses, helps me to gain a better understanding.

 

[Joel Armstrong]

Joel -

I don't know about this pH pen but my experience tells me to always be extra careful with pH measurements as they can be off, sometimes by a lot. I always recommend the following schedule.

1. Calibrate probe - keep the 4 and 7 test packets sealed from air.
2. Test the 4 and 7 pH packets every week.
3. If pH is off on the packet tests, then calibrate. If not, leave for another week.
4. Change packets after 1 month.

Measurement drift is a real thing with these probes, some more than others. The above will allow you to get to know your pH pen and how often you need to calibrate it to keep it on target. At the very least, it will give you confidence in your measurements.

Thank you Art

Greatly appreciated

 

[BigWave]

That's one of the reasons I stopped adding carbonates. I felt I was fighting the soil

This in fact is the basis of the ADA dosing approach. Nearly evey fertilizer product they have contains some kind of kH additive. In fact Seachem Aquavitro has gone to this approach also. Its interesting both these big companies are doing this.