Alk drop after water change

[ofzakaria]

Calibrated the Trident and it got accurate readings per the solution.

After the calibration:

Trident says 6.7 dKH
Hannah says 7.3
Salifert says 7.1

If I can’t trust the Trident to measure accurately, it’s a huge waste of a lot of $

Where do I go from here?
Dose Alk until Trident reads above 7?
Then, I know for sure it’s above 7 no matter what. And I can use Trident’s measurements to hold it steady.

Tough one. But if we assume you used the hannah and salifert correctly, I would follow them if I want to dose. Since they both correlate.
Unless your trident prove to be accurate I would not take dosing decision based on its measurments.

 

[Meshmez]

Hanna claims +-5% of reading, so at 7 dkh that's +-0.35

Trident claims +-0.05

Of course those are just claims.

If it were me I would slowly bring up the baseline to 8ish or higher, so it's in a safer range, and then just look for stability from test to test with the same method.

 

[Meshmez]

You could also test the calibration solution with trident then the other 2 and see if you get the same results.

 

[svreef]

You could also test the calibration solution with trident then the other 2 and see if you get the same results.

That’s a great idea! Too bad I tossed it. Damn it.

 

[Meshmez]

That’s a great idea! Too bad I tossed it. Damn it.

I did this when I first got my Trident because I had he same concerns you do.

The Hanna was off from the Trident calibration solution by the same amount it was off on my tank water compared to the Trident. (though it was within the +-5%)

I also checked the Hanna against their calibration vials, and it was dead on to that...

Soooo... I pretty much just just trust the Trident. I actually spot check with an api kit (it's cheap, and easy) to make sure it's in the ballpark and call it good.

That being said, I don't plan to let the Apex manage dosing based on the Trident. It's easy enough to adjust dosing, so I just keep an eye on my Trident graphs and adjust the doser when I see the graphs trending down.

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[ofzakaria]

I did this when I first got my Trident because I had he same concerns you do.

The Hanna was off from the Trident calibration solution by the same amount it was off on my tank water compared to the Trident. (though it was within the +-5%)

I also checked the Hanna against their calibration vials, and it was dead on to that...

Soooo... I pretty much just just trust the Trident. I actually spot check with an api kit (it's cheap, and easy) to make sure it's in the ballpark and call it good.

That being said, I don't plan to let the Apex manage dosing based on the Trident. It's easy enough to adjust dosing, so I just keep an eye on my Trident graphs and adjust the doser when I see the graphs trending down.

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So measuring a ref. solution that was used to calibrate a tester will yeild a spot on point for the tester that it was calibrated using the ref solution. Its expected, that's how calibration work..
Testing the same ref solution on another tester will not really give much informations.
The ref solution is done to calibrate the trident..
If you want to use ref. Solution you should use one that is independent from all testers.
How would you know the ref solution is actually accurate?

 

[Meshmez]

So measuring a ref. solution that was used to calibrate a tester will yeild a spot on point for the test that it was calibrated using the ref solution. Its expected, that's how calibration work..
Testing the same ref solution on another tester will not really give much informations.
The ref solution is done to calibrate the trident..
If you want to use ref. Solution you should use one that is independent from all testers.
How would you know the ref solution is actually accurate?

I'm not sure why you say that. Assuming the calibration solution is still accurate to what it says on the bottle, it should be.

Whether or not that is a valid assumption is a different story though.

It's the same as calibrating a ph probe and then sticking another probe in the solution to check it.

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[ofzakaria]

I'm not sure why you say that. Assuming the calibration solution is still accurate to what it says on the bottle, it should be.

Whether or not that is a valid assumption is a different story though.

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Do you know what is the solution or chemical used in the cal bottle? Do you know the hannah is built to test such chemical?
Hannah and salifert are built to test salt water, I doubt we know what the calibration chemicals in the cal bottle.

 

[Meshmez]

Do you know what is the solution or chemical used in the cal bottle? Do you know the hannah is built to test such chemical?
Hannah and salifert are built to test salt water, I doubt we know what the calibration chemicals in the cal bottle.

I can try to find the reference where I read this (I believe it was from neptune) , but I believe the cal solution used for the trident is saltwater.

 

[ofzakaria]

I'm not sure why you say that. Assuming the calibration solution is still accurate to what it says on the bottle, it should be.

Whether or not that is a valid assumption is a different story though.

It's the same as calibrating a ph probe and then sticking another probe in the solution to check it.

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As I said unless the ref. solution chemichals is built as a ref chemichal for testers, not only for one specific tester calibration, it's hard to say..
Many test calibration chemicals are built with special chemichal points that matches the tester...
Just think about it, you want to validate an accuracy of a tester by using the tester cal itself..
Maybe thats the engineer in me talking l

 

[Meshmez]

As I said unless the ref chemichal is built ad a ref chemichal for testers, not only for one specific test it's hard to say..
Jist think about it, you want to validate an accuracy of a tester by using the tester cal itself..
Maybe thats the engineer in me talking l

If the cal solution is some crazy chemical specific to Trident, I agree with you. But I believe it is saltwater.

 

[ofzakaria]

I can try to find the reference where I read this (I believe it was from neptune) , but I believe the cal solution used for the trident is saltwater.

If the cal solution is some crazy chemical specific to Trident, I agree with you. But I believe it is saltwater.

I actually almost SURE it is not seawater. Try to calibrate the trident using sea water or aquarium water that is similar kh if thatd the case
It must be a chemichal specific to the trident and specific to the shelve life of the bottle.
It's not sea water..

 

[Meshmez]

I actually almost SURE it is not seawater. Try to calibrate the trident using sea water or aquarium water that is similar kh if thatd the case
It must be a chemichal specific to the trident and specific to the shelve life of the bottle.
It's not sea water..

I can't find the reference that I thought said it was saltwater.

Each bottle (I assume each lot) has different values for alk/cal/mag.
I'm not a chemist, but it would seem if it were some chemical it would be consistent. I would also be surprised if there was a chemical that would react with the reagents in a way to yield alk/cal/mag results in the normal ranges.

The "calibration" vials for the Hanna I'm almost certain are just tinted water. So for these I agree, if you poured them out and tested with a different tester they wouldn't work.

The fact that the Hanna tested the calibration solution anywhere close to the same value also leads me to believe it's simply saltwater, or some other equivalent that should read the same.

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[ofzakaria]

I can't find the reference that I thought said it was saltwater.

Each bottle (I assume each lot) has different values for alk/cal/mag.
I'm not a chemist, but it would seem if it were some chemical it would be consistent. I would also be surprised if there was a chemical that would react with the reagents in a way to yield alk/cal/mag results in the normal ranges.

The "calibration" vials for the Hanna I'm almost certain are just tinted water. So for these I agree, if you poured them out and tested with a different tester they wouldn't work.

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If its indeed seawater then you can practically use any aquarium water that is at that reference in term of paramaters.
Or better yet, most LFS sell sea water, you can buy 5G of "calibration" solution for 5$.
The reason I do not think it's simple sea water is 2 fold
1- seawater chemichal vary based in where you collect from, ahors vs deep sea. U can easily see that by buying sea water and test it. I even fill my tanks with natural sea water that is collect it on the day of delivery and it can vary.
2- sea water will evaporate and I doubt it can have long shelve life without changing paramaters. Simple evident is that if you mix salt water now, test its alk, leave it for a week and test again. U will see variant even without evaporation.
They have to add chemichals to increase the shelve life and to match their equommt design calibration proccess to make sure its consistent..
Ofcourse I am not 100% sure. Just thinking of the above logic make me doubt its simple sea water..

 

[Meshmez]

If its indeed seawater then you can practically use any aquarium water that is at that reference in term of paramaters.
Or better yet, most LFS sell sea water, you can buy 5G of "calibration" solution for 5$.

Yes but you don't know what the values are for the LFS sea water...

 

[ofzakaria]

Yes but you don't know what the values are for the LFS sea water...

U see..same logic, how you think a vendor will be able to get a consistent seawater that come with the same paramaters every single batch?
Look at literature out there, levels measured in sea always come in range not spot on numbers..
Why do not you do a simple search. What is the natural sea water alk and ca levels. See if you can find single point. It will always be reported as a range.

 

[Meshmez]

U see..same logic, how you think a vendor will be able to get a consistent seawater that come with the same paramaters every single batch?
Look at literature out there, levels measured in sea always come in range not spot on numbers..
Why do not you do a simple search. What is the natural sea water alk and ca levels. See if you can find single point. It will always be reported as a range.

I assume they test it with much more sophisticated testing systems and then label it... Each bottle of calibration solution has different alk/cal/mag values. It's not like ph solution where it's always 7.00

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[ofzakaria]

I assume they test it with much more sophisticated testing systems and then label it... Each bottle of calibration solution has different alk/cal/mag values. It's not like ph solution where it's always 7.00

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Sure..maybe...

 

[Meshmez]

This is on the Neptune page. I do recognize that "our calibration seawater sample" is still open to interpretation though. For what its worth, I just tested the salinity of an old (previously opened) bottle of calibration solution and it has a salinity of 36ppt.

 

[Coral reefer]

I say raise (slowly) until your at 8 on the trident. It’s primarily about stability imo, not so much the number. If it’s between 8-8.5 and very stable then you will Be good to go.