Hanna Calcium checker

Emma01 · Feb 2, 2019

Hi
Anyone familiar with the Hanna calcium checker and know whether the temperature of the RO/DI water will affect the overall result? On the box it says accurate @25C. Does that include the RO/DI water temp or is that just the tank temp?
Thanks
Emma

lapin · Feb 2, 2019

I would think temp matters. In higher end devices they have "temperature compensation"
https://www.specmeters.com/nutrient-management/nutrient-meters/calcium/laqua-twin-calcium-meter/
Now I could be wrong because its two different methods.

Emma01 · Feb 2, 2019

lapin said:
I would think temp matters. In higher end devices they have "temperature compensation"
https://www.specmeters.com/nutrient-management/nutrient-meters/calcium/laqua-twin-calcium-meter/
Now I could be wrong.

That looks like a nice piece of kit!
It’s worth a try..... I’ll warm my RO/DI up to 25 and see what happens.
This could be why I’m getting lower end readings?
HOWEVER, I did check Mg today too (not a test I usually undertake) and it is 1155. Ca - 375
Does GFO lower calcium/magnesium?

Rechecked calcium using RO/DI at 25C just now, and it seems the temp of the RODI does make a difference.....

RODI not at 25c-. 375
RODI at 25c- 386
(Still low I know)

Thanks
Thanks

ckalupa · Feb 2, 2019

That is not much variance considering the accuracy of the Hanna checker. Possibly within the normal deviation range. Not to say temperature does not matter but I would guess a couple back to back same-method tests may result in that same small variance too.

Larry L · Feb 2, 2019

ckalupa said:
That is not much variance considering the accuracy of the Hanna checker. Possibly within the normal deviation range. Not to say temperature does not matter but I would guess a couple back to back same-method tests may result in that same small variance too.

Agree, temp will make some difference but it's hard to tell because the specs don't say how much the readings vary by temp. They do say the meter is rated for +/- 6% of the reading, so if you got a reading of 386 at 25C could mean an actual calcium level anywhere between 363 and 409.