Triton says high nutrients, test kits and lfs say otherwise?

[A Young Reefer]

So I have sent an ICP-OES and an N-DOC analysis test a few days ago, and on the same day I have tested everything and so did my lfs. Both showed phosphates of 0.03 (hannah) and 0 nitrates (not the best thing Ik) (salifert). Today I have received my results and it showed that I have elevated phosphorus of 60, phopshate of 0.184, and 16 nitrates. moreover high levels of nitrogen and organic carbon.
The numbers are not my concern, the accuracy of the test is however. which one should I believe? Could’ve the shipping process maybe altered the results?
another reason I am considering believing the icp is because I am currently facing cyano/algae which is one common symptom related to elevated nitrogen.

 

[blaxsun]

There was an analysis posted not that long ago that seemed to indicate that the longer a sample sat the more the overall numbers got skewed (but probably not as much of a variance as you're seeing).

I like using Nyos to test my nitrates and phosphates against my Hanna testers. I'm not necessarily suggesting that you run out and buy additional test kits, but it's often the only way to rule one result out over the other.

 

[Randy Holmes-Farley]

I do not know which, if either, is more accurate.

I'm not convinced that there's enough information available to make claims like nitrogen or organic carbon is too high.

 

[Dan_P]

So I have sent an ICP-OES and an N-DOC analysis test a few days ago, and on the same day I have tested everything and so did my lfs. Both showed phosphates of 0.03 (hannah) and 0 nitrates (not the best thing Ik) (salifert). Today I have received my results and it showed that I have elevated phosphorus of 60, phopshate of 0.184, and 16 nitrates. moreover high levels of nitrogen and organic carbon.
The numbers are not my concern, the accuracy of the test is however. which one should I believe? Could’ve the shipping process maybe altered the results?
another reason I am considering believing the icp is because I am currently facing cyano/algae which is one common symptom related to elevated nitrogen.

Doesn’t NDOC provide total nitrogen? The nitrate is calculated right? The ICP method seems to struggle with P.

Which test kits are being used?

 

[A Young Reefer]

Doesn’t NDOC provide total nitrogen? The nitrate is calculated right? The ICP method seems to struggle with P.

Which test kits are being used?

Hannah for phosphate
Salifert for nitrate

 

[Dan_P]

Hannah for phosphate
Salifert for nitrate

A provisional explanation is that the test kits being used usually provide reasonably accurate measurements and will likely be closer to the truth compared to ICP P accuracy which suffers from the sample being shipped and unknown variation in the ICP method. I think NDOC reports total nitrogen not nitrate. The number reported is a combination of nitrate and organic N. If the nitrate is low, the NDOC result is mostly from organic N.

 

[A Young Reefer]

A provisional explanation is that the test kits being used usually provide reasonably accurate measurements and will likely be closer to the truth compared to ICP P accuracy which suffers from the sample being shipped and unknown variation in the ICP method. I think NDOC reports total nitrogen not nitrate. The number reported is a combination of nitrate and organic N. If the nitrate is low, the NDOC result is mostly from organic N.

thank you.
yes you are right it says N/NO3: 15.51

 

[Rollman]

I don’t do multiple tests for that reason. Just stick with a test, be consistent.

 

[A Young Reefer]

I don’t do multiple tests for that reason. Just stick with a test, be consistent.

yeah I am definitely not gonna change anything in the tank based on the triton, if corals look happy I am happy.