Hanna Alkalinity Reagents

[Mickeyt1reef]

Has anyone noticed any differences in outcomes/results when changing Hanna Alkalinity Reagents. I have received replacement reagents that read constantly 1dkh different than the replacement. The first time it happened, I was out of my current reagent when the replacement arrived. Since I was out i relied on the current results resulting in a drop in dkh. Since then I have insured that i have reagent on hand when the replacement arrived. I have tested them against each other and one read in the low 9s and one in the mid 8s consistently. Now i don't care since they read consistent i just switch over and keep/maintain the new reading. I was just curious if anyone else has experienced this.

 

[shred5]

You will see that with pretty much every hobby grade test kit.
Stability is the key...

Also some reagents can change little as they age.

 

[Kennya]

Yep, same here although I had an increase of 0.6dKH rather than a fall. There is a post somewhere on here I read a few weeks back where a contributor mentions that the alkalinity reagent bottles contain more than the 25ml required to undertake 25tests so you shouldn’t use all the reagent, i.e. the dregs and that the reagents are only really viable for 2-3 months once opened. I’ve now started to note the date and marking off tests as I do them on the side of the bottle.

 

[GoVols]

Well you guys are not crazy, there is a limited time to use when opening a new reagent

Hanna Alk Reagents / Floating Particles

Hello Hanna, I can never finish a bottle of new reagent before floating particles come in to play after half the bottle is used. I've shaken before use every time per refill and not on some refills. Same results. It's a big enough issue to through the test results off by 2 dkh at times. When I...

www.reef2reef.com

 

[Dr. Jim]

I just got a new bottle and noticed my readings were much lower.

I also got the Hanna Standard to check the accuracy of the checker. I was surprised to see the Standard is set to 98 ppm +/- 10 !! 10ppm is about 0.5dKH. That is a huge error swing for a Standard Solution!! It almost seems like, "What's the point?"

(The Phosphorus Standard is good though....not a significant error range).

I get frustrated with any of the alkalinity test kits. I sometimes compare these four:
-Salifert (I think is generally too high)
-Red Sea (I think tends to be low)
-Hanna
-GHL probe
…...and get numbers all over the place! And, there isn't always a pattern where one is consistently higher than the other. I tend to go mostly with the GHL and Hanna.

 

[Mickeyt1reef]

Well you guys are not crazy, there is a limited time to use when opening a new reagent

Hanna Alk Reagents / Floating Particles

Hello Hanna, I can never finish a bottle of new reagent before floating particles come in to play after half the bottle is used. I've shaken before use every time per refill and not on some refills. Same results. It's a big enough issue to through the test results off by 2 dkh at times. When I...

www.reef2reef.com

I have seen the floaters!

 

[GoVols]

I have seen the floaters!

Yeah,
I've seen it read high at the bottom without the floaters as well.

I still like it, but if you don't test alk all the time, it will raise about .5 dKH from bottle to the next bottle, in the same batch.

I guess oxygen plays a roll, once you open a new reagent.