Thread: Help with Hanna multimeter Nitrite readings.

Just got a Hanna Hi83303 photometer for aquaculture because I thought it may be easier to accurately decipher the results than the colour charts on test kits, but I am baffled by the results .



I understand that a reading above 0.2 mg/l No would be considered a poor reading a poor reading using a conventional test strip


I get a clear 0.0 mg/l nitrite reading on a Columbo test kit


On the Hanna reading I get
NaNo2 = 36ppm
N02-N =7 ppm
No2-24 =24ppm

Chemistry is definitely beyond me could anyone please explain which chemform I should use and how I decipher a good results without blowing my brains.

Thanks Shaun.

Originally Posted by Koiforsutherland

Just got a Hanna Hi83303 photometer for aquaculture because I thought it may be easier to accurately decipher the results than the colour charts on test kits, but I am baffled by the results .



I understand that a reading above 0.2 mg/l No would be considered a poor reading a poor reading using a conventional test strip


I get a clear 0.0 mg/l nitrite reading on a Columbo test kit


On the Hanna reading I get
NaNo2 = 36ppm
N02-N =7 ppm
No2-24 =24ppm

Chemistry is definitely beyond me could anyone please explain which chemform I should use and how I decipher a good results without blowing my brains.

Thanks Shaun.

You only need to measure NO2^-N
The other readings are technical stuff for people like me who should get out more so you don't want to worry about them.

Electronic meters can't read the full value of the Nitrite (NO2) molecule. They can only read NO2^-N values which only refers to the Nitrogen part of the NO2 molecule so the reading should be multiplied by the correction factor 3.29 to get the full value of Nitrite (NO2).

A reading of 7 ppm NO2^-N multiplied by 3.29 is 23.03 ppm Nitrite (NO2) which is very high. Are you sure the reading is 7 ppm, not 7 µg/L (micrograms per litre)?

The maximum tolerable value of nitrite for koi is 0.2 ppm (mg/L) regardless of which type of test kit or meter is being used so, if it was 7 µg/L , the Nitrite in the sample would be 0.023 mg/L (ppm) which is quite good but, obviously, could be better if it was nearer to zero.

I've tried to make a full explanation but simplified. If any of it doesn't make sense, please ask and I'll have another go.

It’s a great bit of kit and makes reading results so much easier and more reliable

Originally Posted by Koiforsutherland

Ph seems a little low, reading 7.6 and think it should be reading 8.1/ 8.2 due to buffering kh.

Do you have to calibrate?

The Hanna pH test is based on the Phenol Red test reagent which is very accurate and you can't calibrate them anyway so, if it reads 7.6 pH, that will be an accurate value but don't worry, pH 7.6 is in the middle of the acceptable range so it's a good reading. What is the KH value?

Originally Posted by Koiforsutherland

Hi, The KH and GH is always zero from my tap water and takes a lot of bicarbonate/ buffer powders to raise.

I used to try and keep the KH around 6 but this pushed the PH up to 8.2 and I used to worry that should I get ammonia spike in the summer for any reason it would become toxic very quick and worried about the TDS going up with lots of Bicarbonate.

I have been keeping a close eye on the ph using a Seneye and throwing a cup of bicarbonate after cleaning the bead if I have noticed the Ph diminishing at all.

After a few probs recently I decided I was going to try and keep the pond more in line with guidance increasing the KH to 6-7.

I have been using a KH/GH buffer powder and now the PH is absolutely flatline solid according to Seneye at 8.2 but new Hanna meter says PH 7.6.

I understand that GH is not important but cannot get the GH to raise more than 1 on the liquid testers.

Seneye readings can drift so I would trust the Hanna. You can approximately judge the pH of the reacted Hanna sample by comparing it by eye to the chart below. If the Hanna is correct, the sample would be reddish. If the Seneye reading is correct, the sample would be nearer to mauve.

Phenol Red colour range (with text).jpg

A very low GH is a positive advantage in koi keeping so I wouldn't try to raise it. Just continue to raise the pond KH/pH with sodium bicarbonate which is much cheaper than proprietary KH/GH raisers which are mainly just sodium bicarbonate anyway.

When I looked at the Seneye they advised that the readings were inaccurate in a low KH environment, consequently I didn’t buy one.

i wonder if you have some distilled water you can test as I assume that has a ph of 7 so a good comparator?

You can buy specific calibration water to make sure you are getting good readings.

Originally Posted by Djstiles999

When I looked at the Seneye they advised that the readings were inaccurate in a low KH environment, consequently I didn’t buy one.

i wonder if you have some distilled water you can test as I assume that has a ph of 7 so a good comparator?

Sorry but distilled water can't be used as a pH standard once it's been exposed to the air because its KH is zero so carbon dioxide from the atmosphere dissolves into it and lowers its pH usually to between 5 pH and 6 pH.

Syd, every day is a learning day, hadn’t thought about the KH point

Originally Posted by Djstiles999

Syd, every day is a learning day, hadn’t thought about the KH point

I does the best I can to explain stuff but sometimes my brain scares me