Calibrating The Seneye Free Ammonia Sensor

[Dan_P]

https://www.reef2reef.com/threads/new-cycle-seneye-vs-api.859493/#post-9370206
.04 here's the thread. the nano reef it was baselined on with one tiny fish and packed wall to wall in surface area was not running truly at .04 but that suffices for a baseline, and it suffices there to show api will show dark green in a tank that has no ammonia issues.

anyone who read or saw that api reading/color in that thread above, taken on it's own, would in unison agree the tank isn't cycled. but paired with a calibrated seneye, we didn't even need to trim it into the thousandths to make use of the seneye reading portion.

There is a possible missing chapter in this story: temperature and pH. Free ammonia which the Seneye detects can be undetectable but the API test says differently when the pH is low. We would need to pair up Seneye readings with temperature and pH of the water in which it was submerged to back calculate the total ammonia which the API test detects.

 

[brandon429]

and that is why I'm so glad you have this machine :) :)

 

[Garf]

There is a possible missing chapter in this story: temperature and pH. Free ammonia which the Seneye detects can be undetectable but the API test says differently when the pH is low. We would need to pair up Seneye readings with temperature and pH of the water in which it was submerged to back calculate the total ammonia which the API test detects.

As far as seneye is concerned it calculates total ammonia from pH and free ammonia, presumably temperature. Not a very good strike rate if temperature and pH is off.

 

[Dan_P]

As far as seneye is concerned it calculates total ammonia from pH and free ammonia, presumably temperature. Not a very good strike rate if temperature and pH is off.

Agreed.

Calibrate, calibrate, calibrate analytical devices and methods :)

 

[Garf]

Agreed.

Calibrate, calibrate, calibrate analytical devices and methods :)

Probably a good job ammonia in a running reef is always under control, unless someone lobs some ammonia in, or some other weird event, lol.

 

[Dan_P]

Probably a good job ammonia in a running reef is always under control, unless someone lobs some ammonia in, or some other weird event, lol.

I am going to be looking at that when the current project is completed. I will first dose the experimental aquaria with ammonia and monitor disappearance with the Seneye before trying it on the tank with the pet fish :)

 

[Garf]

I am going to be looking at that when the current project is completed. I will first dose the experimental aquaria with ammonia and monitor disappearance with the Seneye before trying it on the tank with the pet fish :)

You could call her Ami. (Test subject No1)

 

[Dan_P]

You could call her Ami. (Test subject No1)

:)

 

[Randy Holmes-Farley Verified Community Expert]

If I had a Seneye, one thing I’d do as a test is measure a seawater solution with low but detectable free ammonia and fairly low pH, then substantially raise the pH with a very small volume hydroxide or carbonate addition, and see how the free and total ammonia changes. Obviously free ammonia should rise, but not total ammonia.

 

[Garf]

If I had a Seneye, one thing I’d do as a test is measure a seawater solution with low but detectable free ammonia and fairly low pH, then substantially raise the pH with a very small volume hydroxide or carbonate addition, and see how the free and total ammonia changes. Obviously free ammonia should rise, but not total ammonia.

I'd chip in to buy you one, I know times are difficult for successful expert chemists at the minute. We would certainly believe your results.

 

[BeanAnimal]

I'd chip in to buy you one, I know times are difficult for successful expert chemists at the minute. We would certainly believe your results.

I would chip in too...

 

[BeanAnimal]

Not money.. a billionaire like Randy doesn't need the money. I would chip in homemade bacon, it is a lab must-have for long hours of testing.

 

[Dan_P]

If I had a Seneye, one thing I’d do as a test is measure a seawater solution with low but detectable free ammonia and fairly low pH, then substantially raise the pH with a very small volume hydroxide or carbonate addition, and see how the free and total ammonia changes. Obviously free ammonia should rise, but not total ammonia.

Would this serve as a validation that the sensing film response to free ammonia is not sensitive to pH?

 

[avocadoman]

What a great thread. Does anyone have any idea of explanation why Seneye doesn't calculate and give a total ammonia reading? It would be very useful while cycling a tank, given how small changes in pH dramatically affect the free concentration.

 

[Randy Holmes-Farley Verified Community Expert]

Would this serve as a validation that the sensing film response to free ammonia is not sensitive to pH?

I assumed it calculated a total ammonia and the idea was to test that methodology. But if it doesn’t, it’s a less useful test.

 

[Dan_P]

What a great thread. Does anyone have any idea of explanation why Seneye doesn't calculate and give a total ammonia reading? It would be very useful while cycling a tank, given how small changes in pH dramatically affect the free concentration.

I don’t know whether it does somewhere on its app.

I would not trust the calculation because at least for my Seneye’s temperature, pH and free ammonia measurement needed calibration. Any calculation using these measurements would produce a poor estimation of the total ammonia. If you always measured the free ammonia with Seneye at the same temperature and pH, you would obtain a relative measure of free ammonia, data suitable to trend the decline in total ammonia over time. Not sure it would be worth the effort. I am going to be using the Seneye in experimental aquaria. If I discover an easy way around this, I will post it.

 

[taricha]

https://www.reef2reef.com/threads/new-cycle-seneye-vs-api.859493/#post-9370206.04 here's the thread. the nano reef it was baselined on with one tiny fish and packed wall to wall in surface area was not running truly at .04 but that suffices for a baseline, and it suffices there to show api will show dark green in a tank that has no ammonia issues.

Just for kicks, and because I'm an API fan - what if we take Dan's calibration data and run it back on that thread.....

From the thread....

And todats Seneye vs. API - I have made no changes to the tank at all. NH3 consistently dropping slowly on the Seneye - looks as thought its lower on the API too. pH is dropping slowly - will see how things are at the weekend when I do a 20% water change. (the little spike in pH is when we transferred the seneye to the Evo last night...)

0.037 seneye at pH 7.82.
From Dan's chart, his seneye reading 0.037 could correlate to somewhere around ~0.13ppm actual free ammonia. And if we run that on a free ammonia calculator with 7.82pH and 0.13ppm free ammonia.....

The calculator says that would correspond to ~4ppm total ammonia, which frankly looks a LOT like the API test color.
So with Dan's calibration chart, they don't actually disagree at all - but seneye and API both point to maybe 4-ishppm total ammonia.

 

[brandon429]

Thanks for posting I was waiting for the day when you and Dan got this play toy :)

Why in your view within that thread did a two year old nano reef running tiny fish and packed full of ammonia consumers register as 4 ppm total / problematic ammonia? Are you thinking that some two year old nanos full of coral and surface area and no apparent mass source and some tiny fish might be running that day to day?

This strikes you as a system unable to control free ammonia at the .00x level?

This was an excellent benchmark nano in the thread to show that Api can cause false alarms, this tank needs no help.

He didn’t trim his seneye down to the .00x running levels but we can safely say his .04 reading is the base safety line. We didn’t have to trim it to reference that as his baseline


i wish we had him run the api test on that nano he used to benchmark the seneye.

The reading you state you believe is accurate at barely sublethal levels of ammonia (below .05 as the going number from prior threads on toxicity max) comes from that two year old nano reef. It's not in ammonia distress at all. It runs in total control, no where near toxicity, day to day.

 

[Dan_P]

Just for kicks, and because I'm an API fan - what if we take Dan's calibration data and run it back on that thread.....



From the thread....




0.037 seneye at pH 7.82.
From Dan's chart, his seneye reading 0.037 could correlate to somewhere around ~0.13ppm actual free ammonia. And if we run that on a free ammonia calculator with 7.82pH and 0.13ppm free ammonia.....

The calculator says that would correspond to ~4ppm total ammonia, which frankly looks a LOT like the API test color.
So with Dan's calibration chart, they don't actually disagree at all - but seneye and API both point to maybe 4-ishppm total ammonia.

Nice pulling the loose threads together.