TEST METER FOR TESTING NITRATES

[rkpetersen]

Let me know how it work for you...Just a note....If you don't keep your salinity at or near 35ppt the regression will be off...It will be consistent but it will be consistently high...I currently don't have a salinity correction for this test but am considering working on one...If you look earlier in the post Randy comments on this very thing....

Thanks for the note, I will follow up. Fortunately my salinity is always very close to 35 ppt.

 

[jsker]

off topic, which 10 ml pipette are you using?

 

[reefluvrr]

Thank you for doing all that tedious and impressive work!
I can't wait to try it out.

 

[Jason mack]

Great thread ...following a long!!!

 

[Rick Mathew]

Yes, that the interference was the same makes sense. [emoji3]

How much one worries about the interference depends on how accurate one wants the reading. IMO, hardly anyone needs values closer than +/- 10%.

How much of a salinity change would give a 29% error, assuming everything else was perfect?

Randy: Thanks for the reply....I agree +/- 10% would be great...Good thought about the salinity change that would give the 29% error...So much to learn!!

 

[Ray668]

Following along great info

 

[ckalupa]

Does anybody know why they have never developed this for marine at Hannah? Seeing as how it is one of the important parameters that we watch. Actually, I thought I saw some archive of the unit somewhere on the Internet by them

 

[aarbutina]

Good Stuff @Rick Mathew. As I was going to do some testing today, including nitrate using the Red Sea Pro Kit, i figured why not just give this a try and break out the LR Nitrite tester I purchased by accident. Visually the sample tested some where between 1 and 2 ppm (probably closer to 1 ppm). Using the nitrite check and your regression equation I obtained a value of 1.69 ppm. I'd say that is good enough for government work. I should also note that I typically run my tank at a salinity around 33 ppm. If i remember correctly from what I read in this thread, it was noted that at a lower salinity the results could be skewed high. All the same its still in the right ball part.

Again great work.

 

[ckalupa]

@Rick Mathew - to confirm my understanding of the process - In your video using the ULN you got a reading of 83. So plugging it into the equation on the graph you have about 4.3 nitrate?

Nice work and very thorough!

 

[Randy Holmes-Farley Verified Community Expert]

Does anybody know why they have never developed this for marine at Hannah? Seeing as how it is one of the important parameters that we watch. Actually, I thought I saw some archive of the unit somewhere on the Internet by them

Chloride/salinity interference.

 

[TheEngineer]

Would this work for Salifert NO3 tests too? Wondering since you mention both Red Sea and Nyos.

 

[Rick Mathew]

@Rick Mathew - to confirm my understanding of the process - In your video using the ULN you got a reading of 83. So plugging it into the equation on the graph you have about 4.3 nitrate?

Nice work and very thorough!

Thank you

Your understanding is correct...The reading on the video is using the HI-736 Checker...The equation you plugged the "83" reading into was developed for the HI-764 Meter...This would generate a value of 4.3 as you state an "83" reading on the HI-736 would have yielded a value of about 1ppm...Each meter has its own separate regression equation...

 

[Rick Mathew]

Good Stuff @Rick Mathew. As I was going to do some testing today, including nitrate using the Red Sea Pro Kit, i figured why not just give this a try and break out the LR Nitrite tester I purchased by accident. Visually the sample tested some where between 1 and 2 ppm (probably closer to 1 ppm). Using the nitrite check and your regression equation I obtained a value of 1.69 ppm. I'd say that is good enough for government work. I should also note that I typically run my tank at a salinity around 33 ppm. If i remember correctly from what I read in this thread, it was noted that at a lower salinity the results could be skewed high. All the same its still in the right ball part.

Again great work.

Thank you sir....Based on my quick look at the salinity effect I would say your number is about right. I am doing some addition work related to salinity level and its effect on the measurement...will post it when I get it done

 

[Rick Mathew]

Would this work for Salifert NO3 tests too? Wondering since you mention both Red Sea and Nyos.

Good question...Not sure...what is the color of the salifert NO3 test results?...Each Hanna Meter has a specific light source and is selected based on the color of the end test solution...if the Salifert test is red you should be able to do the same thing I did with the Red Sea...You would need to run the standards and generate a regression for that specific test...hope this helps

rick

 

[GoVols]

Thank you

Your understanding is correct...The reading on the video is using the HI-736 Checker...The equation you plugged the "83" reading into was developed for the HI-764 Meter...This would generate a value of 4.3 as you state an "83" reading on the HI-736 would have yielded a value of about 1ppm...Each meter has its own separate regression equation...

Rick,
In your video your using the Red Sea kit and putting 10 ml into the Hanna vial.
Can it be done with the Salifert kit or does it need to be the Red Sea?

 

[Rick Mathew]

Thank you for doing all that tedious and impressive work!
I can't wait to try it out.

Thank you....let me know how it goes...Just a reminder that salinity level effects the outcome...I am working on better quantifying this and will post it when I get it completed

rick

 

[GoVols]

Good question...Not sure...what is the color of the salifert NO3 test results?...Each Hanna Meter has a specific light source and is selected based on the color of the end test solution...if the Salifert test is red you should be able to do the same thing I did with the Red Sea...You would need to run the standards and generate a regression for that specific test...hope this helps

rick

So your study is based off .35 and the Red Sea kit?

 

[Rick Mathew]

Rick,
In your video your using the Red Sea kit and putting 10 ml into the Hanna vial.
Can it be done with the Salifert kit or does it need to be the Red Sea?

Good question...Not sure...what is the color of the salifert NO3 test results?...Each Hanna Meter has a specific light source and is selected based on the color of the end test solution...if the Salifert test is red you should be able to do the same thing I did with the Red Sea...You would need to run the standards and generate a regression for that specific test...hope this helps

 

[Rick Mathew]

off topic, which 10 ml pipette are you using?

Here is the one I use https://www.amazon.com/gp/product/B0167YXPKY/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

 

[Rick Mathew]

Thanks for the note, I will follow up. Fortunately my salinity is always very close to 35 ppt.

Will be very interested to see how it works for you...