Hanna alk checker

Idoc · Oct 20, 2019

taricha said:
Whoa. I think they changed recipe in recent years and it sounds like you have the new chemicals and the old card somehow!

Well that's just great! So my Alk measurements have been reading higher than the actual levels.

I just finished the Elegant Corals dino treatment and was using that wrong alk number and my pH to monitor the levels of CO2... luckily no fish losses.

X-37B · Oct 20, 2019

I use hanna 95% of the time for over 2.5 years. Seems very accurate to me as I have gone through many bottles.
I always back it up with Salifert which is always within .3 of Hanna.
I also have Elos which is accurate too but only to .5.
I dont think the numbers matter that much with whatever you are using as long as its "consistant and Stable".
Bottom line have a backup measurement system and go for "stability".

taricha · Oct 20, 2019

Idoc said:
Well that's just great! So my Alk measurements have been reading higher than the actual levels.

Look for a light green between blue and yellow. See the pic on the link I posted earlier. That would confirm you have the right kit but wrong card.

rmurken · Oct 20, 2019

taricha said:
From Hanna site.
”Accuracy @ 25°C/77°F ±0.3 dKH [or] ±5% of reading"
So at alk of 10, the uncertainty is actually 0.5dkh.

I can’t argue with you there. I just have some fish, some inverts and some zoas. No SPS. Nothing but coralline and some snails for Alk demand. So I am not bothered by the ±.5 dkh level of uncertainty as long as the results are consistent. The Red Sea Pro titration test generally puts my Alk at mid-7’s. Hanna Checker puts it at mid-8’s. But they are basically consistent both internally and with each other as to size of any change in Alk. My pH of 8.2ish might suggest the RS test is closer to the truth, but honestly it seems like my measurement tools are not even close to the precision I’d need to draw any conclusions. So I go back to my tank being fine.

Randy Holmes-Farley · Oct 20, 2019

fcmatt said:
I always wondered why they needed 2 diff units for ppm versus dkh. Why can't one display both? Is there a valid reason?

no.
Also, In reality, neither unit makes good sense to use. The strongly preferred unit is meq/l. Scientists do not use dKH or ppm for alkalinity.

taricha · Oct 20, 2019

rmurken said:
So I am not bothered by the ±.5 dkh level of uncertainty as long as the results are consistent. The Red Sea Pro titration test generally puts my Alk at mid-7’s. Hanna Checker puts it at mid-8’s. But they are basically consistent both internally and with each other as to size of any change in Alk.

I think that's the right way to think about it. I agree that the level of uncertainty doesn't matter as long as the user takes a laissez faire approach and doesn't overreact to fluctuations in the test.

homer1475 · Oct 21, 2019

I think where a lot of people fail with the Hanna ALK meter is using up the last of the reagent intsead if just using the stated 25 tests(yes there is more reagent then 25ML).

I noticed when I got past 25 tests they started to go higher then what they actually were. Once I started tracking the amount of tests in each reagent bottle is when I started to notice a trend of higher DKH when I got past 25 tests. I now simply mark each test on the bottle and throw them away after 25 tests. Much more consistent results.

PatW · Oct 21, 2019

Idoc said:
That's the test I use... and I have a different card!!! What the heck??? I see that green hue and go past it everytime to try to get to red like my card says to do (which is yellow in my samples)... lol

Here's mine:

New test goes from blue to green to yellow. The end point is a shade of yellow-green with no blue. It is a bit subjective.

BeejReef · Oct 21, 2019

homer1475 said:
I think where a lot of people fail with the Hanna ALK meter is using up the last of the reagent intsead if just using the stated 25 tests(yes there is more reagent then 25ML).

I noticed when I got past 25 tests they started to go higher then what they actually were. Once I started tracking the amount of tests in each reagent bottle is when I started to notice a trend of higher DKH when I got past 25 tests. I now simply mark each test on the bottle and throw them away after 25 tests. Much more consistent results.

I was totally unaware of that. Ty. Been a real source of frustration. The test is so reliable, and then suddenly it's way off.
I'm better at picking out errant readings now that have found stability, but when you're trying to find a dose and are expecting variance, an oddball result can really throw you... particularly bc the darn thing is so reliable. It'll reliably give you the same wrong reading twice.. lol.

Brew12 · Oct 21, 2019

homer1475 said:
I think where a lot of people fail with the Hanna ALK meter is using up the last of the reagent intsead if just using the stated 25 tests(yes there is more reagent then 25ML).

I noticed when I got past 25 tests they started to go higher then what they actually were. Once I started tracking the amount of tests in each reagent bottle is when I started to notice a trend of higher DKH when I got past 25 tests. I now simply mark each test on the bottle and throw them away after 25 tests. Much more consistent results.

I don't test enough to ever get to 25 tests before mine gets off. I find that once it's been open for around 2 months it starts reading off.

Idoc · Oct 21, 2019

Brew12 said:
I don't test enough to ever get to 25 tests before mine gets off. I find that once it's been open for around 2 months it starts reading off.

I was thinking of getting this Hanna Alk checker...i think i might stick with titration testing.

I found @Randy Holmes-Farley DIY Alk checking method that @taricha mentioned in a post above. Sounds accurate... but im not sure I want to be dealing with HCl acid in the house... mainly the fumes off HCl!

melanotaenia · Oct 21, 2019

homer1475 said:
I think where a lot of people fail with the Hanna ALK meter is using up the last of the reagent intsead if just using the stated 25 tests(yes there is more reagent then 25ML).

I noticed when I got past 25 tests they started to go higher then what they actually were. Once I started tracking the amount of tests in each reagent bottle is when I started to notice a trend of higher DKH when I got past 25 tests. I now simply mark each test on the bottle and throw them away after 25 tests. Much more consistent results.

No, it is because their reagent bottle are not consistent from batch to batch, that is the main problem.

Oldreefer44 · Oct 21, 2019

For what it's worth my last ICP test matched my Hanna at 8.2 DKH while Red Sea read 9.6 and Salifert read 9.8.

Randy Holmes-Farley · Oct 21, 2019

Idoc said:
I was thinking of getting this Hanna Alk checker...i think i might stick with titration testing.

I found @Randy Holmes-Farley DIY Alk checking method that @taricha mentioned in a post above. Sounds accurate... but im not sure I want to be dealing with HCl acid in the house... mainly the fumes off HCl!

the standard acid has zero fumes. It is not at all like concentrated HCl.

Randy Holmes-Farley · Oct 21, 2019

OLDREEFER44 said:
For what it's worth my last ICP test matched my Hanna at 8.2 DKH while Red Sea read 9.6 and Salifert read 9.8.

just to clarify, that was not done by icp. It’s done by whatever method that company uses. It might just be an alk kit.

taricha · Oct 24, 2019

Idoc said:
I found @Randy Holmes-Farley DIY Alk checking method that @taricha mentioned in a post above. Sounds accurate... but im not sure I want to be dealing with HCl acid in the house... mainly the fumes off HCl!

Like randy said, it’s dilute acid. Only 0.1 molar. No noticeable fumes, and likely a lot less concerning than other test kit chemicals we already use frequently.

diy Alk thread.

DIY Alk test discussion thread

In case anyone wants to discuss the DIY alkalinity test that I recently published, I've started this thread. Here's the article: A DIY Alkalinity Test: By Randy Holmes-Farley - REEFEDITION Happy Reefing!

www.reef2reef.com