Alk Test Discrepancy: Red Sea vs. Hanna

[rmurken]

Fellow reefers: I am now the proud owner of a Hanna marine alkalinity checker (dKh version). Up until now, I’ve been using the Red Sea Foundation Pro Alk test.

RS gives me 7.6 dKh. Hanna 8.6. Same water, same time. Double-checked both.

I wouldn’t expect them to be identical, but a 1 dKh difference makes me question both of them.

Would appreciate any thoughts, insight or experience.

Thanks!

 

[Realposition]

Mine is 1dkh different from my salifert test. You can either buy or make an alk standard and test each kit against it to see which is right or just pick one and use it consistently. Stable alk is typically more important than the actual number within reason.

 

[rmurken]

Making a DIY standard would actually be a fun project...although I’m going to admit up front that my accuracy is likely to be worse than 1 dKh!

 

[Waynerock]

One thing I found helps with consistency get a adjustable pipette from Amazon. It was 32.00 last year but I can adjust from 1ml to 10.9ml and it pulls correct every time. They are prob cheeper now. I do test a lot so there was quite a bit of value in it for me all I have to do is turn the dial for the measurement and push a button.

 

[rmurken]

One thing I found helps with consistency get a adjustable pipette from Amazon. It was 32.00 last year but I can adjust from 1ml to 10.9ml and it pulls correct every time. They are prob cheeper now. I do test a lot so there was quite a bit of value in it for me all I have to do is turn the dial for the measurement and push a button.

Good call. Thanks.

 

[Larry L]

Also FWIW a reading of 8.6 on the Hanna dKH checker could actually be anywhere from 7.9 to 9.3, according to the manufacturer's reported accuracy specs. Not sure what the accuracy of the Red Sea kit might be.

 

[kasso187]

Fellow reefers: I am now the proud owner of a Hanna marine alkalinity checker (dKh version). Up until now, I’ve been using the Red Sea Foundation Pro Alk test.

RS gives me 7.6 dKh. Hanna 8.6. Same water, same time. Double-checked both.

I wouldn’t expect them to be identical, but a 1 dKh difference makes me question both of them.

Would appreciate any thoughts, insight or experience.

Thanks!

I got almost the same results going from RS alk test to hanna alk tester. I chaulk it up to human error and I bet that if you went all the way till the RS test went over and subtract the last drop...I think the result would be a lot closer to the Hanna.

 

[soeminpaing]

I compared hana with redsea and salifert and the difference were 0.2-0.4 dkh. Do you measured the end point of titration or the color of the liquid?