Hanna Nitrate Low Range w/ dilution VS High Range: 28% difference!

[Muffin87]

I made a large water change today, and thought'd it be "fun" to compare results between the new Hanna Nitrate High Range 782, and the old Low Range 781 using the dilution step.

	781 Low Range diluted	782 High Range	Percentual Difference
Before Water Change	24,9	33	27,9%
After Water Change	11.6	15,4	28,1%

First of all, both checkers are pretty precise. The test procedure is repeatable on both, giving very similar percentage differences between the values.
Not sure which checker one is more accurate tho? (more accurate = number on the checker is closer to the amount of NO3 in the water sample)
I mean plus/minus 28% is a big difference!

Wish I could run an ICP test for a more accurate NO3 reading now!

 

[Tamberav]

Looks close enough not to matter to me.

I would use whichever is easier/faster to use.

 

[Dan_P]

I made a large water change today, and thought'd it be "fun" to compare results between the new Hanna Nitrate High Range 782, and the old Low Range 781 using the dilution step.

	781 Low Range diluted	782 High Range	Percentual Difference
Before Water Change	24,9	33	27,9%
After Water Change	11.6	15,4	28,1%

First of all, both checkers are pretty precise. The test procedure is repeatable on both, giving very similar percentage differences between the values.
Not sure which checker one is more accurate tho? (more accurate = number on the checker is closer to the amount of NO3 in the water sample)
I mean plus/minus 28% is a big difference!

Wish I could run an ICP test for a more accurate NO3 reading now!

Obtaining an ICP result would not answer your qustion about accuracy. You would just have a third number.

Buy a nitrate standard and repeat the test exactly with the standard. Multiple parameter standard solutions (containing a mixture of PO4, NO3 standards in one solution are not very expensive.

 

[blaxsun]

I would use whichever is easier/faster to use.

That won't be the low-range, lol.

 

[DrZoidburg]

One could make a reference solution. With a pretty accurate scale and a little math.

 

[marcus07]

can you do the test again at under 5ppm nitrates? id be interested in seeing how close the high range is to the low range when in the low range scale.

 

[Muffin87]

can you do the test again at under 5ppm nitrates?

In the process of cycling a new tank right now. will report back.
It's a bare bottom, so it's gonna take sometime!

 

[Viet658]

Curious if you diluted with freshly mixed salt water or if you just used rodi

 

[Muffin87]

Curious if you diluted with freshly mixed salt water or if you just used rodi

I used freshly mixed salt water. You can't use rodi.