HANNA VS ICP, way different numbers..

[IPT]

Let me say I have been having some hair algae issues.. It is most notable in my Frag tang where there is no Rabbitfish :).

I've had my eye on No3 and Po4. I test using the HANNA devices and the reagent is stored around 70 degrees and in a dry place. I make sure the test tubes are totally clean before using them, and fill them to the line. (though I just had a thought about that I'll come back too).

I've done 2 recent ICPs tests N03 of 25.58, and 22 while my HANNA (tested sampling the water at the same time) came back at 11.2 and 9.7.

For the P04 ICP was .1 and .13, while the HANNA was .07 and .08.

So, my tests seem to be lower that the actual (?), or at least what the (hopefully more accurate) ICP says. I believe the ICP test based on my Algae.

How can I sort this out?

To the other point, the lines in the HANNA tubes wore off long ago. Somehow before that happened I used syringes. I always ended up being 9.3 ml (based on the syringe) to get to the line on the test tube. Maybe I have a volume error?

 

[X-37B]

I just mark the line with a file and fill to it. Mine have been close enough to icp that I call it good.
Algae is not due to your no3 or po4 levels.
I run po4 .1-.2 and no3 5-10 and its been 26 with no algae issue in my 150.

 

[BeanAnimal]

ICP does not test for nitrate and phosphate. They (ICP vendors) are using the same testing methods for those that we use at home.

 

[CHSUB]

Since your nutrients are fairly high does it matter what they actually are?…I’m not commenting to be “funny” or anything but in either case your nutrients are too high imo. If the tank is healthy it shouldn’t really matter what the values actually are; I would guess the actual value is close to the middle.

 

[IPT]

I just mark the line with a file and fill to it. Mine have been close enough to icp that I call it good.
Algae is not due to your no3 or po4 levels.
I run po4 .1-.2 and no3 5-10 and its been 26 with no algae issue in my 150.

A file for the line, great idea!

So what do think would cause the Algae if not the nutrients? RO/DI water tested good as well.

 

[X-37B]

Whats your cleanup crew and tank size?.
For my 150 I have:
8 emerald crabs
Several hermits
1 urchin
70+ different types of snails
Tomini tang

 

[IPT]

Since your nutrients are fairly high does it matter what they actually are?…I’m not commenting to be “funny” or anything but in either case your nutrients are too high imo. If the tank is healthy it shouldn’t really matter what the values actually are; I would guess the actual value is close to the middle.

I hear you. You think No3 of 9.7 and P04 of .07 are too high? That doesn't seem very high. Maybe the P04 is a bit elevated.

None the less, my tank is healthy in many respects. Sans for the Algae and I would say my SPS colors are more muted in my tank then the pieces were when I first got them.

My intention would be to bring them down. A - to see if it helps the Algae issue, and B - to see if it helps my coral color up and be less muted.

It would be nice to have a reliable number though. Is there a standardized solution or reagent to "calibrate" too?

 

[IPT]

Whats your cleanup crew and tank size?.
For my 150 I have:
8 emerald crabs
Several hermits
1 urchin
70+ different types of snails
Tomini tang

120 display, 40 breeder as the Frag tank. In the frag tank I have a small Scopas tang, a small Yellow Eye tang, a lawn mower blenny and a handful of Astrea snails. Fish get traded in as they get bigger. I'm 100% certain the Display tank the Large Rabbitfish cleans up shop. He's a beast at cleaning.

 

[Christoph]

ICP does not test for nitrate and phosphate. They (ICP vendors) are using the same testing methods for those that we use at home.

Hi BeanAnimal,

i think i have responded to this statement before. Likely no reefer uses ion chromatography or a professional photometer (for orthophosphate) at home. This is also very expensive and specialized equipment and very different from methods people use at home.


all the best, Christoph

 

[BeanAnimal]

Hi BeanAnimal,

i think i have responded to this statement before. Likely no reefer uses ion chromatography or a professional photometer (for orthophosphate) at home. This is also very expensive and specialized equipment and very different from methods people use at home.


all the best, Christoph

Thanks Christoph. I certainly would not argue that your photometer may be far better than the Hanna hobby toy or Trident, etc. even if the base chemistry is the same. I did not know that you used ion chromatography for nitrate. Do you know if this is standard for other ICP vendors?

My point was not to imply that your (or other vendor) results for phosphate and nitrate lack accuracy. It was more to the point that it is not ICP.

P.S. I am not finished with my phosphate tester yet, but results should rival commercial lab equipment. Given my project completion rate, there is a chance that it never gets finished…

 

[CHSUB]

You think No3 of 9.7 and P04 of .07 are too high

My po4 is similar now with no negative observable effects. Your No3 is 3500% higher than mine, however I really don’t know if that can produce negative effects? However, I believe aquariums do best when they mimic nature and I have a fairly easy time maintaining nutrients near or slightly above natural levels. I don’t think lowering your nutrients would help with algae but better maintenance would, and this better maintenance will show up as lower nutrient values on test kits and may improve color.

 

[Randy Holmes-Farley]

Let me say I have been having some hair algae issues.. It is most notable in my Frag tang where there is no Rabbitfish :).

I've had my eye on No3 and Po4. I test using the HANNA devices and the reagent is stored around 70 degrees and in a dry place. I make sure the test tubes are totally clean before using them, and fill them to the line. (though I just had a thought about that I'll come back too).

I've done 2 recent ICPs tests N03 of 25.58, and 22 while my HANNA (tested sampling the water at the same time) came back at 11.2 and 9.7.

For the P04 ICP was .1 and .13, while the HANNA was .07 and .08.

So, my tests seem to be lower that the actual (?), or at least what the (hopefully more accurate) ICP says. I believe the ICP test based on my Algae.

How can I sort this out?

To the other point, the lines in the HANNA tubes wore off long ago. Somehow before that happened I used syringes. I always ended up being 9.3 ml (based on the syringe) to get to the line on the test tube. Maybe I have a volume error?

What company?

I’m not sure I’d expect any algae difference between those numbers. Both will allow substantial algae growth if not checked by herbivores.

I’d the company is calculating phosphate from icp phosphorous, it may well be higher due to it detecting a wider range of forms of P.

 

[IPT]

What company?

I’m not sure I’d expect any algae difference between those numbers. Both will allow substantial algae growth if not checked by herbivores.

I’d the company is calculating phosphate from icp phosphorous, it may well be higher due to it detecting a wider range of forms of P.

It was ATI:

Nutrients
NO3 Nitrate 22.49 mg/l Ideal value: 2.00 mg/l ABOVE NORMAL Attention
P Phosphorus 41.79 μg/l Ideal value: 15.51 μg/l ABOVE NORMAL Attention
PO4 Phosphate 0.13 mg/l Ideal value: 0.05 mg/l ABOVE NORMAL Attention

 

[IPT]

I do 10% water changes every week. Tank has about 90x turnover with a return pump, Nero 3, Mp 40, Mp 10, and a Gyre. It's also bare bottom, but there is some detritus that builds up sometimes around the base of the rocks and in a corner where there are a ton of Yumas!

I wonder of the greater amount of Algae in the frag tank is because it's essentially the sump and the flow is substantially less? Could be I guess.

 

[Randy Holmes-Farley]

It was ATI:

Nutrients
NO3 Nitrate 22.49 mg/l Ideal value: 2.00 mg/l ABOVE NORMAL Attention
P Phosphorus 41.79 μg/l Ideal value: 15.51 μg/l ABOVE NORMAL Attention
PO4 Phosphate 0.13 mg/l Ideal value: 0.05 mg/l ABOVE NORMAL Attention

OK, so they measure total P by icp and calculate a value for phosphate, which will include a wider range of molecules than does the Hanna. For example, it reports all organics containing P while the Hanna will not.

 

[IPT]

Interesting. So then I can expect their P04 to be a little higher than mine. That's good to know.

I ordered a Salifert N03 test kit to cross check and it looks like it's reads 25mg/l. I think my nutrients have been way higher than the HANNAs had me thinking they were. I was actually dosing some No3 because I thought my No3 kept dipping into single digits.

So what's with the HANNA No3 tester? Is mine drifting? Is there a way to calibrate or test it accuracy? Can I purposly reduce the water volume to inflate the reading to more closely match the Salifert and ICP? It would be nice to actually know a measure I can trust if I am testing and allowing these numbers to fall.

 

[Randy Holmes-Farley]

I don’t know which is more likely to be accurate between the Hanna and Salifert nitrate. One can make a standard, but I’m not sure it is worth the effort. I don’t think exact nutrient level measurement is especially critical. My recommended target ranges include most of the measurements you mention.

 

[BryanM]

It was ATI:

Nutrients
NO3 Nitrate 22.49 mg/l Ideal value: 2.00 mg/l ABOVE NORMAL Attention
P Phosphorus 41.79 μg/l Ideal value: 15.51 μg/l ABOVE NORMAL Attention
PO4 Phosphate 0.13 mg/l Ideal value: 0.05 mg/l ABOVE NORMAL Attention

I would not consider phos @ .13 to be too high, and all of the ICP vendors seem to want this number in the .03-.06 range. I get very nervous about bottom out this nutrient at .06, let alone .03.

I'm afraid to test, but will tonight, my last phos test was .85.... and everything in my tank is looking fantastic.

With your numbers, if things are looking happy, I would just continue to do what you're doing.

As for the hair algae, if it were me, I'd be trying to add a critter or two to eat it.

 

[unchainedcoot]

Interesting. So then I can expect their P04 to be a little higher than mine. That's good to know.

I ordered a Salifert N03 test kit to cross check and it looks like it's reads 25mg/l. I think my nutrients have been way higher than the HANNAs had me thinking they were. I was actually dosing some No3 because I thought my No3 kept dipping into single digits.

So what's with the HANNA No3 tester? Is mine drifting? Is there a way to calibrate or test it accuracy? Can I purposly reduce the water volume to inflate the reading to more closely match the Salifert and ICP? It would be nice to actually know a measure I can trust if I am testing and allowing these numbers to fall.

Last summer I actually had a different experience.

Phosphates were hovering fine as far as I was concerned.

Sent in an ICP and got this

I have a marine master that I use regularly and an egg checker along with multiple lots of reagents so for the next few days I went through all the combos and eventually accepted the discrepancy

 

[Christoph]

Thanks Christoph. I certainly would not argue that your photometer may be far better than the Hanna hobby toy or Trident, etc. even if the base chemistry is the same. I did not know that you used ion chromatography for nitrate. Do you know if this is standard for other ICP vendors?

My point was not to imply that your (or other vendor) results for phosphate and nitrate lack accuracy. It was more to the point that it is not ICP.

P.S. I am not finished with my phosphate tester yet, but results should rival commercial lab equipment. Given my project completion rate, there is a chance that it never gets finished…I j

Hello,


I can’t speak for others, but we have been using ion chromatography (IC) for anions (and major cations) from the start. It is considered the gold standard for nitrate analysis, as it does not suffer from interferences like photometric or colorimetric methods do.


For phosphate, however, photometric methods are still the best approach—they are highly sensitive and generally free from significant interferences. The main challenge with phosphate measurement in shipped samples is its limited stability. That’s why we chemically stabilize phosphate at the time of sampling (as done in the ICP-MS test kit).


Good luck with your project—having an automated and reliable PO₄ tester (and possibly even a controller/manager) for home aquariums would be a great advancement.


All the best,
Christoph