testing irregularities between batches for alk tester

SPotter · 08/14/2012, 07:06 PM

Hanna,
I was nearing the bottom of my bottle for my alk tester so I decided to just open my new bottle and perform my weekly test. The new bottle is batch number 3186 and I got an alk reading of 152 on the meter or 8.8 dkh. I was alarmed by this because last week when I ran my test the reading was 172 or 9.9 dkh. So ran another test using the bottle that used for last weeks test which was batch # 3132 and again I got the same value that I got last week of 172. So I did another test using the new bottle (3186) and again the value on the meter was 152. Can you explain to me why this is happening?

xp964 · 08/15/2012, 07:00 AM

Quote:

Originally Posted by SPotter

Hanna,
I was nearing the bottom of my bottle for my alk tester so I decided to just open my new bottle and perform my weekly test. The new bottle is batch number 3186 and I got an alk reading of 152 on the meter or 8.8 dkh. I was alarmed by this because last week when I ran my test the reading was 172 or 9.9 dkh. So ran another test using the bottle that used for last weeks test which was batch # 3132 and again I got the same value that I got last week of 172. So I did another test using the new bottle (3186) and again the value on the meter was 152. Can you explain to me why this is happening?

Hello SPotter,

Please contact our technical service department with your question. They can be reached by e-mail at [email protected], or by phone at (800)426.6287 ex. 34 or 46.

Thanks for choosing Hanna!

SPotter · 08/15/2012, 07:13 AM

thank you

jcw · 08/15/2012, 07:19 AM

then post back here and let everyone know what they say, please...

SPotter · 08/15/2012, 07:39 AM

will do....email has been sent.

SPotter · 08/15/2012, 08:04 AM

already received response and resolution. A new bottle of reagent is being sent to my home. Very please with how this was handled and resolved very quickly.

BeanAnimal · 08/15/2012, 11:44 AM

Did Hanna confirm that reagent lot (3186) was bad, or did they just offer to replace it because you were having issues?

SPotter · 08/15/2012, 11:57 AM

Quote:

Originally Posted by BeanAnimal

Did Hanna confirm that reagent lot (3186) was bad, or did they just offer to replace it because you were having issues?

they asked if the color of the reagent was light or dark. I advised it was light and they offered to replace it. There was no confirmation as to whether or not it was good or bad.

BeanAnimal · 08/15/2012, 11:59 AM

Interesting....

Blayz77 · 08/18/2012, 09:39 PM

i just checked my alk lot number and it is 3186 as well. i tested my alk 2 days ago with hanna alk checker and salifert test kits and my readings were very similar with eachother.

you might find that making sure the meniscus is on the line in the vial will help to get consistent results. i found this to be very helpful on my calcium checker and have carried it over to my alk checker.

im gonna do some more testing tonight im currently raising my water params up to where i want them. ill report back as reference to the alk readings using batch 3186

BeanAnimal · 08/19/2012, 08:01 AM

Blayz

Most of us are using a syringe to fill the cuvettes...

SPotter · 08/19/2012, 09:26 AM

Quote:

Originally Posted by Blayz77

i just checked my alk lot number and it is 3186 as well. i tested my alk 2 days ago with hanna alk checker and salifert test kits and my readings were very similar with eachother.

you might find that making sure the meniscus is on the line in the vial will help to get consistent results. i found this to be very helpful on my calcium checker and have carried it over to my alk checker.

im gonna do some more testing tonight im currently raising my water params up to where i want them. ill report back as reference to the alk readings using batch 3186

My inconsistencies were from one bottle of reagent to another not one brand kit to another. That being said, I should pick up a salifert kit to see which bottle is bad. to be off by 1 Dkh between bottles would not come from being off a little on the amount of water in the vial.

Sent from my SCH-I510 using Tapatalk 2

Blayz77 · 08/19/2012, 01:20 PM

well using the same batch 3186 i just tested my alk then raised it and tested it again this is my results.

start point
salifert - 7.7
hanna - 7.1

finish point
salifert - 9.0
hanna - 8.7

in both cases the hanna alk tested a little lower but it wasnt so far off that it was like omg.

now on my curvete i was using when i use a 5ml sryinge when i add 10ml of sample water it will put the meniscus over the line. but i have not tested by doing that. instead i fill the curvette until the meniscus is on the line of the curvette.

i know that you do not really care about one test to another but it gives you an idea that with my findings with batch 3186 i find to be fairly accurate when compared to another test kit.

with these hanna checkers it seems that just one extra/less drop of either sample or reagent can send the numbers in wild directions so its important to be very precise and consistant in the measuring.

BeanAnimal · 08/19/2012, 01:34 PM

Blayz,

The problems most of us have had are twofold. 1) differences BETWEEN LOTS and 2) repeatability of results.

Many of us have found that the 10ml line of the cuvettes is very often not properly marked, as measured with a pipette or quality sryinge. For that reason, we ignore the line and use a known accurate tool (pipette or syringe) to fill the cuvette.

In EVERY Hanna alk reagent refill I have used, the add-on plastic sryringe tip fits so loosely on the syringe that it allows air to be drawn in as syringe plunger is pulled and reagent is drawn into the syringe. (workaround? don't use the crappy add-on tip). My "salifert" add-on tips don't leak...

Many of us have had foriegn material (seditment of some kind) in the Alk reagent. Hanna has indicated that they are unaware of any issues and that it is end user contamination (NOT).

When all the little issues are added up, it is no wonder that so many of us are having problems. I am glad you are not

Blayz77 · 08/19/2012, 02:00 PM

i am not using the supplied tip on the hanna kit either for the same reason so i threw it away and have been using a tip from one of my other test kits.

outside of differences between lots or contamination either by end user or factory i can not say which is unfortunate in either case.

more importantly is the repeatability of results. which i think can be done but it has to be very precise and you have to find a method that works for you in obtaining the result you want

for example filling my curvette where the meniscus is on the line and using a 1ml srynge with a usable tip gets me results that are just about right. however if i used 10ml of sample using a sryinge which would put my water level over the line i might need to adjust the amount of reagent used to obtain the same results. but i would need to test this way to verify.

i dunno if you follow what im trying to say but in my testing it is obvious that if you follow the supplied directions your results could vary between tests. the end user can experiment and obtain more accurate results but at a greater cost. it is unfortunate that it has to be this way since i would really like to use these checkers as a sole means to testing but at this time i would not trust the readings without a second opinion. although my alk checker seems to be on par when using less then 10ml of sample water.

BeanAnimal · 08/19/2012, 02:18 PM

Quote:

Originally Posted by Blayz77

i am not using the supplied tip on the hanna kit either for the same reason so i threw it away and have been using a tip from one of my other test kits.

But most folks are using the supplied tip (and know no better). They simply trust the the results.

Quote:

outside of differences between lots or contamination either by end user or factory i can not say which is unfortunate in either case.

Without testing EACH batch against a known standard, you simply can't trust the restults. In context to the problem mentioned aboce (tips) and the one below (cuvette fill line) there is no way these kits can be assumed accurate without a standard.

Quote:

more importantly is the repeatability of results. which i think can be done but it has to be very precise and you have to find a method that works for you in obtaining the result you want

That is the point, due to the built in error rate and all of the variables, the results are not repeatable. Most folks don't understand this and simply trust the results.

Quote:

for example filling my curvette where the meniscus is on the line and using a 1ml srynge with a usable tip gets me results that are just about right. however if i used 10ml of sample using a sryinge which would put my water level over the line i might need to adjust the amount of reagent used to obtain the same results.

Correct, The results are not repeatable with the supplied instructions and tools. Altering the sample volume to get :accurate" results is beyind silly.

I do understand what you were trying to say, but most folks reading along likely understood it to mean that with a little patience, the Alk checker is just peachy... Something we both know is not the case.

I too wish I could trust the results from this (and the other) checkers...

Blayz77 · 08/19/2012, 02:43 PM

agreed that it is very silly in having to experiment at all with these test kits if you going to put a product on the market it should work out of the box and not be so finickey.

the only way for me to trust the results would be to find a formula with the hanna checker that matches the results on other test kits as a standard. the only problem is that you only get like 25 tests with hanna. and by the time your done with finding a good method you have pretty much used half the tests and would possibly need to start all over again when u get a new batch of reagent. which is just ridiculous.

08/14/2012, 07:06 PM	#1
SPotter Registered Member Join Date: Jun 2010 Location: Manasquan, NJ Posts: 3,567	testing irregularities between batches for alk tester Hanna, I was nearing the bottom of my bottle for my alk tester so I decided to just open my new bottle and perform my weekly test. The new bottle is batch number 3186 and I got an alk reading of 152 on the meter or 8.8 dkh. I was alarmed by this because last week when I ran my test the reading was 172 or 9.9 dkh. So ran another test using the bottle that used for last weeks test which was batch # 3132 and again I got the same value that I got last week of 172. So I did another test using the new bottle (3186) and again the value on the meter was 152. Can you explain to me why this is happening? __________________ Steve Current Tank Info: 315g 72x36x28 DT, 80g FT, MRC sump, ATI SUNPOWER 10X80W, ATB 10.5 skimmer, Tunze 2 x 6105 & 2 x 6095, blueline 40HDX

08/15/2012, 07:13 AM	#3
SPotter Registered Member Join Date: Jun 2010 Location: Manasquan, NJ Posts: 3,567	thank you __________________ Steve Current Tank Info: 315g 72x36x28 DT, 80g FT, MRC sump, ATI SUNPOWER 10X80W, ATB 10.5 skimmer, Tunze 2 x 6105 & 2 x 6095, blueline 40HDX

08/15/2012, 07:19 AM	#4
jcw Registered Member Join Date: Oct 2010 Location: elmhurst, il Posts: 1,800	then post back here and let everyone know what they say, please... __________________ I don't think Coral can live very long under Sun light. It's too yellow. ...get yourself some LED's. -eznet2u Current Tank Info: 125g DT, custom 30g sump, custom 29g remote display, ATB elegance, ATB 1800 flowstar, mp40(2)- one failed wetside, mp10(2), remote 55g crytic fuge

08/15/2012, 07:39 AM	#5
SPotter Registered Member Join Date: Jun 2010 Location: Manasquan, NJ Posts: 3,567	will do....email has been sent. __________________ Steve Current Tank Info: 315g 72x36x28 DT, 80g FT, MRC sump, ATI SUNPOWER 10X80W, ATB 10.5 skimmer, Tunze 2 x 6105 & 2 x 6095, blueline 40HDX

08/15/2012, 08:04 AM	#6
SPotter Registered Member Join Date: Jun 2010 Location: Manasquan, NJ Posts: 3,567	already received response and resolution. A new bottle of reagent is being sent to my home. Very please with how this was handled and resolved very quickly. __________________ Steve Current Tank Info: 315g 72x36x28 DT, 80g FT, MRC sump, ATI SUNPOWER 10X80W, ATB 10.5 skimmer, Tunze 2 x 6105 & 2 x 6095, blueline 40HDX

08/15/2012, 11:44 AM	#7
BeanAnimal Registered Member Join Date: Feb 2003 Location: Pittsburgh Posts: 20,342	Did Hanna confirm that reagent lot (3186) was bad, or did they just offer to replace it because you were having issues?

08/15/2012, 11:59 AM	#9
BeanAnimal Registered Member Join Date: Feb 2003 Location: Pittsburgh Posts: 20,342	Interesting....

08/18/2012, 09:39 PM	#10
Blayz77 Registered Member Join Date: Feb 2009 Location: ca Posts: 450	i just checked my alk lot number and it is 3186 as well. i tested my alk 2 days ago with hanna alk checker and salifert test kits and my readings were very similar with eachother. you might find that making sure the meniscus is on the line in the vial will help to get consistent results. i found this to be very helpful on my calcium checker and have carried it over to my alk checker. im gonna do some more testing tonight im currently raising my water params up to where i want them. ill report back as reference to the alk readings using batch 3186

08/19/2012, 08:01 AM	#11
BeanAnimal Registered Member Join Date: Feb 2003 Location: Pittsburgh Posts: 20,342	Blayz Most of us are using a syringe to fill the cuvettes...

08/19/2012, 01:20 PM	#13
Blayz77 Registered Member Join Date: Feb 2009 Location: ca Posts: 450	well using the same batch 3186 i just tested my alk then raised it and tested it again this is my results. start point salifert - 7.7 hanna - 7.1 finish point salifert - 9.0 hanna - 8.7 in both cases the hanna alk tested a little lower but it wasnt so far off that it was like omg. now on my curvete i was using when i use a 5ml sryinge when i add 10ml of sample water it will put the meniscus over the line. but i have not tested by doing that. instead i fill the curvette until the meniscus is on the line of the curvette. i know that you do not really care about one test to another but it gives you an idea that with my findings with batch 3186 i find to be fairly accurate when compared to another test kit. with these hanna checkers it seems that just one extra/less drop of either sample or reagent can send the numbers in wild directions so its important to be very precise and consistant in the measuring.

08/19/2012, 01:34 PM	#14
BeanAnimal Registered Member Join Date: Feb 2003 Location: Pittsburgh Posts: 20,342	Blayz, The problems most of us have had are twofold. 1) differences BETWEEN LOTS and 2) repeatability of results. Many of us have found that the 10ml line of the cuvettes is very often not properly marked, as measured with a pipette or quality sryinge. For that reason, we ignore the line and use a known accurate tool (pipette or syringe) to fill the cuvette. In EVERY Hanna alk reagent refill I have used, the add-on plastic sryringe tip fits so loosely on the syringe that it allows air to be drawn in as syringe plunger is pulled and reagent is drawn into the syringe. (workaround? don't use the crappy add-on tip). My "salifert" add-on tips don't leak... Many of us have had foriegn material (seditment of some kind) in the Alk reagent. Hanna has indicated that they are unaware of any issues and that it is end user contamination (NOT). When all the little issues are added up, it is no wonder that so many of us are having problems. I am glad you are not

08/19/2012, 02:00 PM	#15
Blayz77 Registered Member Join Date: Feb 2009 Location: ca Posts: 450	i am not using the supplied tip on the hanna kit either for the same reason so i threw it away and have been using a tip from one of my other test kits. outside of differences between lots or contamination either by end user or factory i can not say which is unfortunate in either case. more importantly is the repeatability of results. which i think can be done but it has to be very precise and you have to find a method that works for you in obtaining the result you want for example filling my curvette where the meniscus is on the line and using a 1ml srynge with a usable tip gets me results that are just about right. however if i used 10ml of sample using a sryinge which would put my water level over the line i might need to adjust the amount of reagent used to obtain the same results. but i would need to test this way to verify. i dunno if you follow what im trying to say but in my testing it is obvious that if you follow the supplied directions your results could vary between tests. the end user can experiment and obtain more accurate results but at a greater cost. it is unfortunate that it has to be this way since i would really like to use these checkers as a sole means to testing but at this time i would not trust the readings without a second opinion. although my alk checker seems to be on par when using less then 10ml of sample water.

08/19/2012, 02:43 PM	#17
Blayz77 Registered Member Join Date: Feb 2009 Location: ca Posts: 450	agreed that it is very silly in having to experiment at all with these test kits if you going to put a product on the market it should work out of the box and not be so finickey. the only way for me to trust the results would be to find a formula with the hanna checker that matches the results on other test kits as a standard. the only problem is that you only get like 25 tests with hanna. and by the time your done with finding a good method you have pretty much used half the tests and would possibly need to start all over again when u get a new batch of reagent. which is just ridiculous.