Hannah Salinity Checker

[j3ss323]

Hello,

I have a concern.
So I have 2 Hannah salinity checkers and both are displaying different salinity levels.
Hannah 1 : 1.026
Hannah 2 : 1:023
Refractometer : 1.025

I calibrated both with the solution but they still show the same salinity.
I am extremely confused.

Can somebody help?

 

[DSEKULA]

Get a standard solution and check them with it. Once you know the standard is 1.026 you can be certain which is accurate on the other hand the accuracy of this equipment is +-0.001 so you potentially have two meters that are reading within their given accuracy an one that's .001 off

 

[j3ss323]

Get a standard solution and check them with it. Once you know the standard is 1.026 you can be certain which is accurate on the other hand the accuracy of this equipment is +-0.001 so you potentially have two meters that are reading within their given accuracy an one that's .001 off

By standard solution do you mean the packages that come with the Hannah checker?

 

[DSEKULA]

A standard is just a solution that has been mixed to a known solution. I'm not sure of what comes with a Hanna as I don't have one. I own Milwaukee refractometer but also own a mobile water testing lab so I get spoiled and borrow work equipment to test my tank if there's any question
if those are standard solutions there should be one that's marked 1.000sg and another that's 1.026 (or 1.025 or something similar). All you would do is take the three meters and test them with both standards and compare how close they are to the known true number if both numbers are +-0.001 then the meter is within an acceptable range.
If you don't have standards you could always search online for a set of seawater specific gravity standards, there are many brands etc and their generally pretty cheap.

 

[DSEKULA]

As a side note, 1.023-1.026 will keep your reef alive so if everything looks good I would monitor more for fluctuations than a hard number and not overthink it

 

[dadnjesse]

The Hanna calibration fluid is not a standard solution you can't use it on your refractometer.

 

[Dennis Cartier]

I had an issue with my Hanna meter when I first got it where it read far different than my existing hydrometers. At the time I was using a Tropic Marin High Precision hydrometer and an IceCap salinity pen. The wildly different readings that the Hanna was providing, even after calibration prompted me to purchase a few more hydrometers to use as replicates. So now I now have 2 x Tropic Marin High Precision, 1 x Aqua Medic DensiMeter, 1 x Sera hydrometer, 1 x IceCap salinity pen and the Hanna. What I found was that the Tropic Marin's matched each other 100% (down to 0.0001 g/ml), the Aqua Medic read slightly lower, within 0.0005 g/ml. The Sera was in the ballpark, I don't remember the exact difference. The IceCap continued to read about the same as the TM. The Hanna on the other hand always showed my salinity being super low, like 1.022 - 1.023. I tried calibrating it multiple times. Finally I calibrated it with the packet after soaking it in the tank to bring it up to the tank temperature. That seemed to help get the Hanna reading closer to the herd. I just tested it now and it is showing 35.8, which is close, just a bit above the 1.026 that my IceCap is showing. I noticed a month or so ago that the Hanna seems to have got inline with the rest. So what changed? Well a couple of months back I detected that I had some stray voltage in the tank. I was getting precipitate on my grounding probe. I removed all the non essential equipment and the precipitate has stopped, though I never actually found anything leaking current.

So my suggestion would be to try calibrating with a packet at tank temperature, and then perhaps test your water in a glass outside the tank and see if either of those make a difference.

Dennis