Test kit discrepancies

[jgvergo]

I am a year into the hobby and have been using Red Sea test kits (Ca, Alk and Mg). I am pretty science and math savvy and I am sure I'm carefully following the directions on the kits. I hold the droppers vertical, clean my glass, measure the amount of water exactly, make sure when adding powder that it is level (using a razor blade) and I use a digital timer when mixing, etc.

I decided that I would try Salifert recently and bought the Ca and Mg test kits. I get consistently different results from the two kits. Significantly different. For Calcium RS = 475 and Sal = 600. For Mg, RS=1360 and Sal=1550.

I know some people say that maintaining water parameters is the key to success and I am maniacally focused on keeping params stable and on target. However, how can I be sure if I'm "on target" if the testing is inaccurate?

P.S. I know that my Ca and Mg are probably in an acceptable range. Everything is healthy in my tank. Nevertheless, I'd really like to get the water testing down to a science.

P.P.S. When performing a titration, I wait for the color to stop changing, which is typically a few drops after it has started to change.

 

[dew9000]

I have always used Salifert kits. When I needed to buy a new magnesium kit I decided to try the red sea. It looked nice with the case and the syringe holder and had decent reviews. I could never get a consistent reading and they never made sense like magnesium over 1600. Decided to just bite the bullet and buy another Salifert kit even though the red sea still had 95% tests left. Glad I did because my readings were consistent again and lined up with my normal 1300 range. I have read several other posts of inaccurate results for the magnesium kit specifically. I never tried the calcium kit from red sea so I can't comment.

 

[JimWelsh]

+1 for Salifert.

 

[wkscott]

+1 for Red Sea. Depends on the particular test. I have 2 of just about every test. None of the results match very well. I just use the result that gives me the number I am looking for.
C'est la vie.

https://www.reef2reef.com/threads/b...ts-two-rise-to-victory-one-falls-flat.299595/

 

[dew9000]

This is a good read

https://www.reef2reef.com/threads/b...i-hanna-triton-awt.234660/page-3#post-2754827

 

[wkscott]

This is a good read

https://www.reef2reef.com/threads/b...i-hanna-triton-awt.234660/page-3#post-2754827

Thanks but that read made me more confused as to the best tests. I think the manufacturers give us different results so we'll by more kits as a double check. They're all in cahoots!

 

[jason2459]

Thanks but that read made me more confused as to the best tests. I think the manufacturers give us different results so we'll by more kits as a double check. They're all in cahoots!

If you were looking for a single best then that thread should be confusing as there was no single best IMO. There were some obvious ones I would not use however.

Salifert is a safe bet accross any test they provide.

 

[dew9000]

Thanks but that read made me more confused as to the best tests. I think the manufacturers give us different results so we'll by more kits as a double check. They're all in cahoots!

Well maybe haha. Seems like from what I have researched, most Red Sea kits are good I just had issues with the one (magnesium) I tried for the first time. I guess I should have just stuck with what I have been using for 15 years.

 

[jgvergo]

I initially had trouble with the Red Sea Mg test, but it turned out to be my fault. The graphic instructions have a light grey loop that indicates you need to add 5 drops, one at a time with 15 seconds of shaking in between each drop. It was very easy to miss the grey loop and only add one drop instead of 5.

 

[jgvergo]

+1 for Red Sea. Depends on the particular test. I have 2 of just about every test. None of the results match very well. I just use the result that gives me the number I am looking for.
C'est la vie.

https://www.reef2reef.com/threads/b...ts-two-rise-to-victory-one-falls-flat.299595/

"tautological water testing"

 

[roostertech]

One thing to note about the red sea MG test is you have to continuously add titration and stop at the first time it turn blue. If you let it sit too long after blue it will turn purple again and mislead you to add more titration -> arrive at bad reading.

Some other kit (nyos?), have explicit color for when you past stop point.

 

[DereksReef77]

I feel your pain with the test kits giving totally different results. I have been using salifert for a couple of years and started getting weird numbers with them. Long story short was that I had a couple bad boxes of instant ocean salt that was giving me crazy numbers. Before I realized it was the salt I bought api,red sea, nyos,elos, and of course salifert so I'm going to do tests with all of them then send my water to triton for analysis. Triton results should let me know which test kits are the closest to the lab results. Before I can get to all the testing I just went back to salifert.

 

[wkscott]

If you were looking for a single best then that thread should be confusing as there was no single best IMO. There were some obvious ones I would not use however.

Salifert is a safe bet accross any test they provide.

I do have all of the Saliferts. Probably accurate, I just have a real hard time reading the colors.

 

[wkscott]

I initially had trouble with the Red Sea Mg test, but it turned out to be my fault. The graphic instructions have a light grey loop that indicates you need to add 5 drops, one at a time with 15 seconds of shaking in between each drop. It was very easy to miss the grey loop and only add one drop instead of 5.

I have used that kit for 5 years and I have always missed that step until just last week when I caught it.

 

[jsker]

This should help with your testing link

 

[dew9000]

I initially had trouble with the Red Sea Mg test, but it turned out to be my fault. The graphic instructions have a light grey loop that indicates you need to add 5 drops, one at a time with 15 seconds of shaking in between each drop. It was very easy to miss the grey loop and only add one drop instead of 5.

Yeah I followed it to the tee and watched videos on YouTube after I got strange numbers. Even if I got accurate numbers from the red Sea, the 15 seconds between drops is a pain in the but. I even used a stop watch on my phone for each timed step. Salifert seems to be quite a bit faster.

 

[GoVols]

Red Sea Pro for cal and alk... but for the first time ever I got a bad cal refill. lot#1115 / exp-0118.

http://www.reefcentral.com/forums/showthread.php?t=2626940

Mag. - Salifert all the way. Used the RS Pro Mag. test until my intake froze. Got the Salifert and the RS Pro was giving me high readings. Dosed up my mag. to the Salifert and my cal and alk intake kicked back in.

 

[jgvergo]

I feel your pain with the test kits giving totally different results. I have been using salifert for a couple of years and started getting weird numbers with them. Long story short was that I had a couple bad boxes of instant ocean salt that was giving me crazy numbers. Before I realized it was the salt I bought api,red sea, nyos,elos, and of course salifert so I'm going to do tests with all of them then send my water to triton for analysis. Triton results should let me know which test kits are the closest to the lab results. Before I can get to all the testing I just went back to salifert.

Please let us know the results!

 

[jason2459]

I feel your pain with the test kits giving totally different results. I have been using salifert for a couple of years and started getting weird numbers with them. Long story short was that I had a couple bad boxes of instant ocean salt that was giving me crazy numbers. Before I realized it was the salt I bought api,red sea, nyos,elos, and of course salifert so I'm going to do tests with all of them then send my water to triton for analysis. Triton results should let me know which test kits are the closest to the lab results. Before I can get to all the testing I just went back to salifert.

You can compare variance with my results too. That would be interesting. I've compared various kits to each other and Triton and other vendors.

https://www.reef2reef.com/threads/b...i-hanna-triton-awt.234660/page-3#post-2754827