Hana ULR Phosphate checker

[griff500]

Hi again, sorry I still need to clear up the question of zeroing the Hanna. Did you use the reference solution to zero the hanna before testing the same reference solution with the added reagent.

Or did you zero both times with the DT water?

With regards dilution test. I see your point with regards one would expect a much darker colour. The only reason I added this is that you mentioned the colour gradually faded and also mentioned a reading of 0. I am not a chemist so do not know the full process of the red sea test. However I have seen other tests show a false negative if the reading is off the scale. I thought I would just add the suggestion of diluted test just to eliminate that from the process.

Cheers, Tony.

I tested the tank water diluted as per Red Sea instructions and got the same zero reading, as anticipated.

 

[griff500]

One thing about that standard is it only checks the machine (which may be worth doing, certainly) but not the reagents since there's no phosphate involved. It's just a color/absorption standard.

Indeed, and I have had bad batches of reagents before.

 

[griff500]

Out of curiosity (and by no means a way to discredit the test solution you are using), but why haven't you used Hanna's reference solution? I don't know that it would give a different result, but I feel you could be more certain it isn't a reference issue (or if the checker is actually misreading, then Hanna would know you used theirs and maybe it could be replaced).

I wanted to test the Red Sea against the Hanna and see which was correct, plus the reference solution could be used to check other test kits, whereas the Hanna will test one parameter for one test kit...

The Red Sea kit gave exactly the result that was expected, which would be quite a coincidence, unless there was a reputation for only giving a reading of 0.08, but then that would not explain the zero reading from the tank water.

I have had the checker for years (probably at least four) and I wouldn't expect Hanna to replace it after that amount of time. As mentioned by Randy, that would not mean it was a hardware issue as it could be the reagents and I have had bad reagents previously (it's not exactly uncommon with Hanna).

 

[Mindi]

I have been using the Hanna ULR phosphorus for years and can say with certainty that on at least 2 occasions I have had faulty reagent. Suggest dump your reagent and get some new of a different expiry date to see if the difference persists.

 

[griff500]

I have been using the Hanna ULR phosphorus for years and can say with certainty that on at least 2 occasions I have had faulty reagent. Suggest dump your reagent and get some new of a different expiry date to see if the difference persists.

I wouldn't be surprised. I've had the issue a couple of times as well.

 

[Dr RBG]

Hanna seems to make two checkers

 

[Dr RBG]

Hanna makes 2 checkers:
1
PHOSPHATE LOW RANGE COLORIMETER HI713 HANNA CHECKER - FRESH & MARINE WATER
2
PHOSPHORUS ULTRA LOW RANGE COLORIMETER HI736 HANNA CHECKER - MARINE WATER
Would this make a difference since they are not measuring the same thing or are they, Not sure about the math

 

[Thesupa79]

can u get ure hands on a different hannah checker just to compare

 

[Thesupa79]

I can say this, i have done three test in a row on a couple of occasions with the hannah ulr ,and have never got the same reading all three times, once I got two out of three to be the same ,so i went with that...This seems to be the case with nitrates also, when nutrients are so low, i feel accuracy suffers.

 

[MnFish1]

A reference solution surely has the constituents of seawater as far as required for a test to be as accurate as possible with hobby test kits:

Saltwater reference solution (11/2017).
Sal: 33ppt / KH/Alk=9dKH / Ca=435 / Mg=1340 / K=395 / Sr=8 / B=4 / I=0,08 / PO4=0,08 / NO3= (2) / (PH8,1 Non-buffered).

I don't believe that is going to give a false reading based on a 'freshwater' base any more than saltwater mixed from RODI will give a false reading.

Don't forget that the Hanna kit gives a significantly higher reading that the Red Sea kit for the reference solution and for my tank water and the effluent from the reactor.

Your post didnt make it clear that it was a reference solution designed for 'marine' aquaria -only that you used a reference solution with .08 phosphate.... that was the confusion on my part

 

[MnFish1]

The meter was zeroed with tank water (always in the checker, then press to start and press when it says '1'. Take out, add reagent, two minutes of inversion, put it back in and hold the button down for the 3-minute countdown.

The reference solution (0.08) showed last night a reading of 0.15 (from memory) on the Hanna and zero on the Red Sea kit.

Diluting for high range could be worth a try BUT if it is off the chart then I would expect a very dark colour to result - not a very light colour. Wouldn't that be likely?

I have had some hair algae and used GFO primarily - as it was being used I started to get growth and more polyp extension and no other changes were made, so I have to assume phosphate was being reduced and having a positive effect.

You cannot zero the hanna checker with your tankwater - and then use the reference solution as the 'test'... It won't work

 

[Randy Holmes-Farley Verified Community Expert]

Hanna makes 2 checkers:
1
PHOSPHATE LOW RANGE COLORIMETER HI713 HANNA CHECKER - FRESH & MARINE WATER
2
PHOSPHORUS ULTRA LOW RANGE COLORIMETER HI736 HANNA CHECKER - MARINE WATER
Would this make a difference since they are not measuring the same thing or are they, Not sure about the math

They measure the same thing using the same method. The 736 has a bit lower range and less uncertainty.

 

[rcpalmer1]

Hanna makes 2 checkers:
1
PHOSPHATE LOW RANGE COLORIMETER HI713 HANNA CHECKER - FRESH & MARINE WATER
2
PHOSPHORUS ULTRA LOW RANGE COLORIMETER HI736 HANNA CHECKER - MARINE WATER
Would this make a difference since they are not measuring the same thing or are they, Not sure about the math

I have had accuracy problems with Hanna checkers as well. I have both of these testers. I will pull a same in the morning and run it on both checkers and see how close to each other they are.

 

[Kenfishy]

Doesn’t the Hannah checker use a light and photoreceptors? Could be a sensor problem. I accidentally fried my kh checker by getting the electronics wet and the readings were way off and inconsistent. Bought a new one and everything was good.

 

[griff500]

You cannot zero the hanna checker with your tankwater - and then use the reference solution as the 'test'... It won't work

What? That didn’t happen and obviously wouldn’t work.

 

[Tony Thompson]

Hi @griff500 sorry for all the questions, I thought we would just eliminate anything obvious. You obviously take care with your testing procedures and the fact that you use a reference solution is a very positive indication of that. I have a number of reference solutions myself and find them invaluable.

I agree with you that after all your testing and referencing it would suggest that the problem lies either with the reagent or the checker itself. The readings from the two methods against reference solution would certainly give a strong indication of that. As with the majority of hobby grade tests , there will always be some deviation down to tolerance limits and procedure errors. But IMO the scale of the deviation in your case would suggest faulty test equipment. That said it is always best to keep an open mind until the majority of possibilities have been eliminated.

Only thing I could suggest is to ask a fellow reefer to lend you new reagent from a different batch then also try another checker. I would help you out myself but I presume you are in the USA. Please keep us updated of your progress.

Good luck

 

[griff500]

Hi @griff500 sorry for all the questions, I thought we would just eliminate anything obvious. You obviously take care with your testing procedures and the fact that you use a reference solution is a very positive indication of that. I have a number of reference solutions myself and find them invaluable.

I agree with you that after all your testing and referencing it would suggest that the problem lies either with the reagent or the checker itself. The readings from the two methods against reference solution would certainly give a strong indication of that. As with the majority of hobby grade tests , there will always be some deviation down to tolerance limits and procedure errors. But IMO the scale of the deviation in your case would suggest faulty test equipment. That said it is always best to keep an open mind until the majority of possibilities have been eliminated.

Only thing I could suggest is to ask a fellow reefer to lend you new reagent from a different batch then also try another checker. I would help you out myself but I presume you are in the USA. Please keep us updated of your progress.

Good luck

Hi Tony. I'm in not-so-sunny Kent. As you say, it's got to be the hardware or reagent but it's certainly way outside the ballpark.

 

[Tony Thompson]

Hi Tony. I'm in not-so-sunny Kent. As you say, it's got to be the hardware or reagent but it's certainly way outside the ballpark.

Ha ha. there I go making assumptions again. Kent is a bit far south for me, I am up in North Yorks. I think in the USA this would be classed as a stone's throw away, but for me to travel that far south I would need a translator, ha ha. Hope you get sorted.

 

[griff500]

Ha ha. there I go making assumptions again. Kent is a bit far south for me, I am up in North Yorks. I think in the USA this would be classed as a stone's throw away, but for me to travel that far south I would need a translator, ha ha. Hope you get sorted.

And you'd have to check your passport was valid...

 

[rcpalmer1]

So this morning I took a 60ml syringe and drew out 30ml from my DT. I filled 3 test tubes. One for ALK one for Phosphate and one for Phosphorus. Phosphate and Phoshorus were ran the same way. Sample place in machine, button pushed, sample removed and reagent added, tube inverted 100 times, places back in machine, button long pushed, results displayed in 3 minutes. Phosphorous LR reagent HI 713-25 lot H102 EXP 08-2019 was 0.03. Phosphorus Ultra OR reagent HI736-0 lot H071 EXP 05-2020 was 27 or 0.083. That is a difference of 0.053.