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gotfrogs
12/09/2014, 08:42 PM
I just got a Hanna Nitrite ULR (HI 764) Handheld Colorimeter. It provides readings of nitrogen-nitrite in ppb but says if you want to know the concentration of nitrite ion concentration, multiply the reading by 3.29.

I just took my first measurement of my quarantine tank and got a reading of 10ppb. Is my "Nitrite" 10 or 32.9 ppb?

Second question, I know that Nitrite should be zero, but reef keepers normally do not test it with an ultra low range test. What is a true reasonable limit for a quarantine/hospital fish tank?

bertoni
12/09/2014, 09:09 PM
32.9 ppb. :) Nitrite is safe for fish at much higher levels than that.

gotfrogs
12/09/2014, 09:24 PM
Then range of the meter is 0-658 ppb, it I stay within this range and I all good or should I increase water changes at a lower level?

Randy Holmes-Farley
12/10/2014, 05:26 AM
It is very unlikely to get near the top of that range unless it is a cycling tank, but even the top end is likely safe.

This has more:

Nitrite and the Reef Aquarium
http://reefkeeping.com/issues/2005-06/rhf/index.htm

xp964
02/26/2015, 10:58 AM
Hello Everyone,

In the HI764 instruction manual it states to convert the NO2¯-N concentration to the nitrite ion concentration (NO2¯), then multiply the reading by a factor of 3.29.

Nitrite is composed of one Nitrogen and two Oxygen molecules. The combined molecular weight is (14 + 2*16 = 46). Taking the formula weight (46) and dividing by Nitrogen’s weight of 14 = 3.29. When the HI764 displays a reading, it is displaying the Nitrogen component of Nitrite only. For this reason if someone wanted to have the reading as Nitrite instead of Nitrite-Nitrogen the reading is multiplied by 3.29. This is common, as with Ammonia vs. Ammonia-Nitrogen, Nitrate vs. Nitrate Nitrogen and Phosphorous vs. Phosphate.

Since the difference is only a calculation we try to program the meter with the unit of interest by the user. For the HI764 it seems that the Nitrogen component of Nitrite was of interest. We value any input from the end user community.

Please let us know if you have any other questions.
Hanna Instruments USA

bertoni
02/26/2015, 03:57 PM
As a matter of habit, most articles and discussions in the hobby seem to use ppb NO<sub>2</sub>, not ppb N-NO<sub>2</sub>, but either seems okay to me.