Low Alk, low pH results on initial Alkatronic tests

[undermind]

Hey Alkatronic owners! I finished setting up an Alkatronic a few days ago and the initial tests are a little strange. I'm wondering if this is normal.

The first few tests were coming in consistently at 8.67 while my Hanna checker was reading 9.3. The Alkatronic results have been steadily rising over the last 6 tests or so, up to 9.09 now – which is of course closer to the Hanna results.

Now of course, my natural response would be that the Alk is indeed rising in the tank. However, I'm not seeing that with Hanna tests. My buffer also doses around the clock, and Alk consumption has been solid for a few months, with no changes to the dosage of buffer. In other words, I don't believe the Alk is on the rise like the Alkatronic says.

The second issue is that the pH seems to be getting lower and lower according to the Alkatronic. They're coming in about .25 lower than my Apex probe on average. The Alkatronic ranges about 8.01-8.18 but my long term pH is 8.25-8.50 with the Apex. Both probes are calibrated.

Are the pH tests reliable on the Alkatronic? I would expect so since the pH probe is so key to the Alk tests.

I did see in the manual two things:
1) The first two test results may be inaccurate.
2) The pH may show "high" for the first 1-2 days while the probe "adapts to the biological water"

Neither of these seem to be the case since:
1) I've now taken 11 tests
2) The pH is testing low, not high

Thanks for reading! Obviously these are not huge concerns at all, and nothing I'm especially worried about. I'm just curious if any other Alkatronic owners have experienced stuff like this when they started up.

 

[MnFish1]

Hey Alkatronic owners! I finished setting up an Alkatronic a few days ago and the initial tests are a little strange. I'm wondering if this is normal.

The first few tests were coming in consistently at 8.67 while my Hanna checker was reading 9.3. The Alkatronic results have been steadily rising over the last 6 tests or so, up to 9.09 now – which is of course closer to the Hanna results.

Now of course, my natural response would be that the Alk is indeed rising in the tank. However, I'm not seeing that with Hanna tests. My buffer also doses around the clock, and Alk consumption has been solid for a few months, with no changes to the dosage of buffer. In other words, I don't believe the Alk is on the rise like the Alkatronic says.

The second issue is that the pH seems to be getting lower and lower according to the Alkatronic. They're coming in about .25 lower than my Apex probe on average. The Alkatronic ranges about 8.01-8.18 but my long term pH is 8.25-8.50 with the Apex. Both probes are calibrated.

Are the pH tests reliable on the Alkatronic? I would expect so since the pH probe is so key to the Alk tests.

I did see in the manual two things:
1) The first two test results may be inaccurate.
2) The pH may show "high" for the first 1-2 days while the probe "adapts to the biological water"

Neither of these seem to be the case since:
1) I've now taken 11 tests
2) The pH is testing low, not high

Thanks for reading! Obviously these are not huge concerns at all, and nothing I'm especially worried about. I'm just curious if any other Alkatronic owners have experienced stuff like this when they started up.

Are you making sure that the results are being compared at teh same time and same time of day - becasue both can fluctuate.

Whenever a new piece of equipment is broken in - readings can be like this - Do you have your alkatronic 'probe' in the same section of your tank as your apex probe (ie.. any change the apex is closer to a dosing device, etc). I would tend to trust the alkatronic as compared to the Hanna - and I would tend to trust the alkatronic as compared to the apex depending on the age of the apex probe.

The best way to determine which one is 'accurate' or 'more accurate' is to get an independent 3rd test and see which is closer

 

[gbru316]

The best way to determine which one is 'accurate' or 'more accurate' is to get an independent 3rd test and see which is closer

I made a reference standard per RHF's instructions and tested my Hanna. Off by > 0.5 dKh. Purchased a Salifert alk kit, which measured dead-on.

Given that my Trident is calibratable (and I'm assuming Alkatronic is similar), while the hanna isn't, I used my tank water to calibrate after determining alk using salifert.

 

[MnFish1]

I made a reference standard per RHF's instructions and tested my Hanna. Off by > 0.5 dKh. Purchased a Salifert alk kit, which measured dead-on.

Given that my Trident is calibratable (and I'm assuming Alkatronic is similar), while the hanna isn't, I used my tank water to calibrate after determining alk using salifert.

Sorry - so - you cannot use your tank water to calibrate anything. Just like you cannot calibrate a refractometer with 0 TDS RODI. So - You're back to square one from a science/answer to your question standpoint. I personally would not worry about the difference in the tests - trust the one you just paid hundreds of dollars for - and double check it with tests. IMHO though everyone complains about API tests - HANNA tests are very difficult (for me) - and though they give you 'a number' which makes it look more official - I'm not sure that it is

 

[gbru316]

Sorry - so - you cannot use your tank water to calibrate anything. Just like you cannot calibrate a refractometer with 0 TDS RODI. So - You're back to square one from a science/answer to your question standpoint. I personally would not worry about the difference in the tests - trust the one you just paid hundreds of dollars for - and double check it with tests. IMHO though everyone complains about API tests - HANNA tests are very difficult (for me) - and though they give you 'a number' which makes it look more official - I'm not sure that it is

I can control sources of error better with a standard titration kit better than I can with a Hanna or trident or alkatronic.

which is why I trust it. A further reason is because when measuring a known reference, it had zero error. Unlike the other test methods.

so if I test the tank water with a kit with minimal error, then tell the automated tester what the trusted numbers are —- at which point the automated tester numbers match the trusted kit numbers, what would you call it? Calibration is performed to increase accuracy, is it not? It might not be accurate across the entire curve, but for the points around where I use it, it certainly seems to be.

regardless, I only use automated testing for trend analysis and so as long as it measures close to a known value (<0.5 dKh, not almost 1.5 dKh like it was before), it’s good enough for me.

 

[MnFish1]

I can control sources of error better with a standard titration kit better than I can with a Hanna or trident or alkatronic.

which is why I trust it. A further reason is because when measuring a known reference, it had zero error. Unlike the other test methods.

so if I test the tank water with a kit with minimal error, then tell the automated tester what the trusted numbers are —- at which point the automated tester numbers match the trusted kit numbers, what would you call it? Calibration is performed to increase accuracy, is it not? It might not be accurate across the entire curve, but for the points around where I use it, it certainly seems to be.

regardless, I only use automated testing for trend analysis and so as long as it measures close to a known value (<0.5 dKh, not almost 1.5 dKh like it was before), it’s good enough for me.

You should not use tank water to calibrate an instrument.

 

[gbru316]

You should not use tank water to calibrate an instrument.

For every rule, there’s an exception. The key is understanding how and when the exception applies, and what associated risks may manifest.

until I can afford lab grade equipment that interfaces with Apex and automatically doses my tank in accurate and precise quantities (more accurate and precise than apex + trident + dos) round the clock, I’m stuck with the equipment I have.

I’m comfortable with the level of risk I’ve taken by using this method (and so are many others who have adopted this method using the equipment we’ve chosen).

And thats all that matters.

 

[MnFish1]

For every rule, there’s an exception. The key is understanding how and when the exception applies, and what associated risks may manifest.

until I can afford lab grade equipment that interfaces with Apex and automatically doses my tank in accurate and precise quantities (more accurate and precise than apex + trident + dos) round the clock, I’m stuck with the equipment I have.

I’m comfortable with the level of risk I’ve taken by using this method (and so are many others who have adopted this method using the equipment we’ve chosen).

And thats all that matters.

Actually - I agree with you - it's all that matters to you - and thats fine - its your opinion and your tank - and you're probably correct - that it doesn't matter much.

But - since it's a discussion forum I gave my opinion. In general (independent of alkatronics) - the way to decide which of 2 tests is 'correct' is to do a third test (as well as making sure that you're first 2 tests are done correctly). It's also generally accepted that using a known standard is more accurate for calibration of test equipment.

 

[gbru316]

Actually - I agree with you - it's all that matters to you - and thats fine - its your opinion and your tank - and you're probably correct - that it doesn't matter much.

But - since it's a discussion forum I gave my opinion. In general (independent of alkatronics) - the way to decide which of 2 tests is 'correct' is to do a third test (as well as making sure that you're first 2 tests are done correctly). It's also generally accepted that using a known standard is more accurate for calibration of test equipment.

Ultimately, I don’t disagree with your stance.

I used both neptune and fauna marin reference solutions with the trident and was unable to achieve a level of accuracy I was satisfied with. After blowing through $40 or so in reference solutions, I came up with a solution I was satisfied with and that I could verify independently.

The problem is I cannot calibrate just alk, it has to be all 3 (all, ca, mg) at once. The solution I created is only an alk standard. So I used the most accurate test method I have and essentially turned my tank water into an alk standard (and mg, and ca with their respective salifert tests). Of course, if/when I recalibrate next, I’ll have to again test with the salifert to get an accurate value immediately prior to calibration.

My intent here was just to share my experiences with automated testing and offer an alternative for those struggling to gain trust in it.

Besides, automated testing accuracy really doesn’t matter a ton as most of us are not operating at either extremes of the accepted alk range. Precision is what we need. The benefit of automated testing lies in trend analysis, not necessarily the actual value.