HI 736 ULR - Test / Same-Sample Retest Result Variations - Page 2

CalmSeasQuest · 06/22/2012, 05:10 PM

Thanks you Jessica. I assumed the tests would have to be duplicated and that it would take time.

I'm looking forward to their reply.

SpinyReef · 06/23/2012, 09:42 AM

Could it be the microbubbles created by shaking the sample? By the time you re-test, the bubbles have time to make their way to the surface. Just a theory

CalmSeasQuest · 06/23/2012, 10:42 AM

Quote:

Originally Posted by SpinyReef

Could it be the microbubbles created by shaking the sample? By the time you re-test, the bubbles have time to make their way to the surface. Just a theory

I don't think so. Great care was taken not to shake the sample and the cuvette was rolled horizontally to remove any micro bubbles that may have adhered to the wall of cuvette.

No micro bubbles are visible and the results were the same (initial test always provided much higher results) whether the C2 sample was continuously, gently agitated during the 3 minute period, or not.

The fact that similar results (although I did not repeat the tests hundreds of times as were done in this example) were obtained using a different meter and different sample water adds to the puzzle. The good news is it's a simple process to replicate the tests and from there Hanna should be able to come up with an answer as to why the results vary so widely (well beyond the stated accuracy claims for the device) and provide a solution including insight into which numbers should be believed.

BeanAnimal · 06/27/2012, 12:12 PM

To make a long story short, I have (2) of these meters and have gone through several hundred reagent packets out of no less than 6 reagent lots. After the problems with reagent batch 006, I ran a little experiment using several reagent packs out of several batches with the same tank water. I charted the results and was able to pick out each reagent batch by the distribution on the graph. I also spent time sampling with BOTH meters using the same lot and/or using both meters with the same vial.

I have also been able to replicate your issue to some degree, though my initial and time lapsed tests do not show as much of a spread most of the time. I think it may have to do with the overall tank chemistry differences between our (and others who have done similar tests) tanks. I have had some reagent batches that clearly do not easily disolve in the 2 minute time and others that have... or is it that my tank chemistry has been different during these observations over the last year? I dunno, but I do know that getting repeatable results is tough.

My conclusion after extensive use: I find the checker kind of useful as a rough indicator in the same way that test strips are a rough indicator. I honestly feel that there are serious issues with reagent consistency from batch to batch (lets call it quality control) and not sure if it is a problem with active ingredient, sachet volume or some other quality control issue.

In the end, I just don't trust unless I keep another test kit handy and TEST EACH NEW REAGENT LOT against the known good test kit -OR- ensure that I always have reagent from a known good batch so that the new batch can be tested against. In either case, it is a colossal waste of time and money.

For the life of me I can't figure out why Hanna has chosen the foil sachets as a reagent delivery method. plastic or gel capsules that can be pulled apart and dumped are a far more logical choice from a manufacturing standpoint (filling them) and an end users standpoint (using them). If the capsules are not suitable due to lack of a hermetic seal, then a small break open plastic ampule would be a good choice.

Darth Vedder · 07/02/2012, 12:43 AM

Deleted, posted in wrong thread...

Englishmatt · 07/10/2012, 08:39 PM

Well there goes my purchase of the Hanna Phos Checker. I see ZERO point in purchasing a test device if you can't get consistent results, can't trust which results you get and need to compare the results against a known good test kit to be sure the Hanna is accurate...

May as well just stick with the good/known test kit.

Shame too...I currently use the Red Sea Pro kits and the Po4/No3 kit takes almost 20 mins to perform both tests. I was looking forward to the simple approach of the Hanna Systems.

Strange thing is that the general FORUM love these devices. Never read a bad word about them until I came to the Hanna forum...

BeanAnimal · 07/10/2012, 09:12 PM

Most people don't know they have a problem, they just trust the results. What is the old saying... Ignorance is bliss

I think the most frustrating part is that with a little thought, these devices could have been so much better. I had (for a while) thought Hanna would recognize the issues and change or adapt. To that end, many of us have listed the issues over and over. In all honesty, it is pretty clear that they could either care less, or they are incapable of reacting due to their structure or internal processes.

chercm · 07/11/2012, 07:40 AM

hanna does not dare to come back with any reply for such unreliable device

BeanAnimal · 08/21/2012, 08:03 AM

CalmSea...

I have been filling the cuvette, wiping it clean and then letting it sit for 3 or so minutes to allow the water to settle and any suspended bubbles to disolve or rise. I then do C1, add reagent and do C2. The results drop less (but still do) after follow up readings.

chercm · 08/28/2012, 06:01 PM

Quote:

Originally Posted by BeanAnimal

CalmSea...

I have been filling the cuvette, wiping it clean and then letting it sit for 3 or so minutes to allow the water to settle and any suspended bubbles to disolve or rise. I then do C1, add reagent and do C2. The results drop less (but still do) after follow up readings.

the 2 viral method have more consistent reading ....

BeanAnimal · 08/28/2012, 07:34 PM

Not really...

Giovanni · 10/20/2012, 08:01 AM

I am looking at buying one of these. Any update from Hanna?

xp964 · 10/22/2012, 11:04 AM

We have not received any update from the Chemistry or R&D departments at Hanna Inc.

igadget56 · 03/05/2013, 10:45 AM

Did anyone get an answer from Hanna? I have never, NEVER seen customer service this bad. I have ordered products directly from China with excellent customer service. If I worked for Hanna I would be so embarrassed, I wouldn't
tell ANYONE.

CalmSeasQuest · 03/08/2013, 02:05 PM

Quote:

Originally Posted by igadget56

Did anyone get an answer from Hanna? I have never, NEVER seen customer service this bad. I have ordered products directly from China with excellent customer service. If I worked for Hanna I would be so embarrassed, I wouldn't
tell ANYONE.

Sadly, no. Hanna failed to even respond.

redadeath · 03/19/2013, 09:22 PM

is there any updates i think ..... nothing from hanna

does the kh tester do the samew too ??

06/22/2012, 05:10 PM	#26
CalmSeasQuest Registered Member Join Date: Sep 2009 Location: Brighton, MI Posts: 1,135	Thanks you Jessica. I assumed the tests would have to be duplicated and that it would take time. I'm looking forward to their reply. __________________ -Tom The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man. - George Bernard Shaw Current Tank Info: AI SOL Blue Powered Mixed Reef, Maxspect G2 FT, Desktop Nano/CSQ DIY Skimmer (View my Home Page for more info.) - Tanks Managed Via Apex.

06/23/2012, 09:42 AM	#27
SpinyReef Registered Member Join Date: Mar 2012 Location: Qc, Canada Posts: 239	Could it be the microbubbles created by shaking the sample? By the time you re-test, the bubbles have time to make their way to the surface. Just a theory __________________ 150g Shallow SPS dominated reef.

06/27/2012, 12:12 PM	#29
BeanAnimal Registered Member Join Date: Feb 2003 Location: Pittsburgh Posts: 20,298	To make a long story short, I have (2) of these meters and have gone through several hundred reagent packets out of no less than 6 reagent lots. After the problems with reagent batch 006, I ran a little experiment using several reagent packs out of several batches with the same tank water. I charted the results and was able to pick out each reagent batch by the distribution on the graph. I also spent time sampling with BOTH meters using the same lot and/or using both meters with the same vial. I have also been able to replicate your issue to some degree, though my initial and time lapsed tests do not show as much of a spread most of the time. I think it may have to do with the overall tank chemistry differences between our (and others who have done similar tests) tanks. I have had some reagent batches that clearly do not easily disolve in the 2 minute time and others that have... or is it that my tank chemistry has been different during these observations over the last year? I dunno, but I do know that getting repeatable results is tough. My conclusion after extensive use: I find the checker kind of useful as a rough indicator in the same way that test strips are a rough indicator. I honestly feel that there are serious issues with reagent consistency from batch to batch (lets call it quality control) and not sure if it is a problem with active ingredient, sachet volume or some other quality control issue. In the end, I just don't trust unless I keep another test kit handy and TEST EACH NEW REAGENT LOT against the known good test kit -OR- ensure that I always have reagent from a known good batch so that the new batch can be tested against. In either case, it is a colossal waste of time and money. For the life of me I can't figure out why Hanna has chosen the foil sachets as a reagent delivery method. plastic or gel capsules that can be pulled apart and dumped are a far more logical choice from a manufacturing standpoint (filling them) and an end users standpoint (using them). If the capsules are not suitable due to lack of a hermetic seal, then a small break open plastic ampule would be a good choice. Last edited by BeanAnimal; 06/27/2012 at 12:53 PM.

07/02/2012, 12:43 AM	#30
Darth Vedder Sith Lord Join Date: Jan 2012 Location: Saint Charles, MO Posts: 426	Deleted, posted in wrong thread... Last edited by Darth Vedder; 07/02/2012 at 01:19 AM.

07/10/2012, 08:39 PM	#31
Englishmatt Registered Member Join Date: Apr 2012 Location: Woodstock, GA Posts: 162	Well there goes my purchase of the Hanna Phos Checker. I see ZERO point in purchasing a test device if you can't get consistent results, can't trust which results you get and need to compare the results against a known good test kit to be sure the Hanna is accurate... May as well just stick with the good/known test kit. Shame too...I currently use the Red Sea Pro kits and the Po4/No3 kit takes almost 20 mins to perform both tests. I was looking forward to the simple approach of the Hanna Systems. Strange thing is that the general FORUM love these devices. Never read a bad word about them until I came to the Hanna forum... __________________ DT Info: 150G (48x30x24), Berlin 400 Sump, INS-180 Skimmer, BP Reactor, Reeflo Barracuda Gold Return, 2 x MP40s, 2 x Radions, APEX Base w/wxm, JBJ ATO Current Tank Info: 270G System (150G DT, 40G Refugium, 40G QT, 30G Sump) - Amm 0ppm, Nitrite 0ppm, Nitrate 0ppm, Po4 .1ppm, pH 8.14, kH 10, Ca 460, mg 1400, Salinity 1.024-25

07/10/2012, 09:12 PM	#32
BeanAnimal Registered Member Join Date: Feb 2003 Location: Pittsburgh Posts: 20,298	Most people don't know they have a problem, they just trust the results. What is the old saying... Ignorance is bliss I think the most frustrating part is that with a little thought, these devices could have been so much better. I had (for a while) thought Hanna would recognize the issues and change or adapt. To that end, many of us have listed the issues over and over. In all honesty, it is pretty clear that they could either care less, or they are incapable of reacting due to their structure or internal processes.

07/11/2012, 07:40 AM	#33
chercm Registered Member Join Date: Apr 2006 Location: Singapore Posts: 1,930	hanna does not dare to come back with any reply for such unreliable device

08/21/2012, 08:03 AM	#34
BeanAnimal Registered Member Join Date: Feb 2003 Location: Pittsburgh Posts: 20,298	CalmSea... I have been filling the cuvette, wiping it clean and then letting it sit for 3 or so minutes to allow the water to settle and any suspended bubbles to disolve or rise. I then do C1, add reagent and do C2. The results drop less (but still do) after follow up readings.

08/28/2012, 07:34 PM	#36
BeanAnimal Registered Member Join Date: Feb 2003 Location: Pittsburgh Posts: 20,298	Not really...

10/20/2012, 08:01 AM	#37
Giovanni Moved On Up Join Date: Mar 2005 Location: KY Posts: 1,467 Blog Entries: 8	I am looking at buying one of these. Any update from Hanna? __________________ Giovanni Most of My Money I Spent On Whiskey and Women, The Rest I Just Waisted!

10/22/2012, 11:04 AM	#38
xp964 RC Sponsor Join Date: Apr 2005 Location: RI Posts: 464	We have not received any update from the Chemistry or R&D departments at Hanna Inc. __________________ Hanna Instruments USA Smithfield, RI http://www.hannainst.com/usa

03/05/2013, 10:45 AM	#39
igadget56 Registered Member Join Date: Jun 2011 Posts: 433	Did anyone get an answer from Hanna? I have never, NEVER seen customer service this bad. I have ordered products directly from China with excellent customer service. If I worked for Hanna I would be so embarrassed, I wouldn't tell ANYONE.

03/19/2013, 09:22 PM	#41
redadeath Registered Member Join Date: Apr 2011 Posts: 307	is there any updates i think ..... nothing from hanna does the kh tester do the samew too ??