Hannah salinity (problems?) v. Neptune and Refractometer

[ScottB]

Get the VEEGEE STX 3 refractometer and forget about it. I had the cheaper BRS recfractometer, it sucks

I only have calibrate the VEEGEE about once every 6-8 months and it only off by a tiny amount

^+1 for VeeGee. Same experience.

 

[Richard Newman]

Hello @offtropic.
I noticed your Mag at 1500. Is that correct? Many test kits document Mag readings above 1400 will influence the testing of other elements, salinity included.

If it is that will def affect the readings on a refractometer as they directly relate to a control solution. Unfortunately I don't recall which way it will push the error. As a contributor to the thread above yes, it's quite the rabbit hole.

You can alway make your own conductivity control solution. I did, it matches the Hanna control solution and now I have a secondary check. It is rather easy to make if you have a good kitchen scale.

1. 182ml = 182g RODI
2. 6.2g Mortons Iodized salt (just a few grains more than 1/4 tsp)

As other's have mentioned here and in other threads, don't get stuck with an absolute number. Just keep it consistent to the tool you are measuring it with.

Hope this helps.

Cheers!

 

[offtropic]

Hello @offtropic.
I noticed your Mag at 1500. Is that correct? Many test kits document Mag readings above 1400 will influence the testing of other elements, salinity included.

If it is that will def affect the readings on a refractometer as they directly relate to a control solution. Unfortunately I don't recall which way it will push the error. As a contributor to the thread above yes, it's quite the rabbit hole.

You can alway make your own conductivity control solution. I did, it matches the Hanna control solution and now I have a secondary check. It is rather easy to make if you have a good kitchen scale.

1. 182ml = 182g RODI
2. 6.2g Mortons Iodized salt (just a few grains more than 1/4 tsp)

As other's have mentioned here and in other threads, don't get stuck with an absolute number. Just keep it consistent to the tool you are measuring it with.

Hope this helps.

Cheers!

My Mg has always been high and I'm not sure exactly why...might need to test that with another kit as well! I think it pushes the refractometer higher so actually increases my concern. I'm definitely not hung up on absolute numbers especially if they aren't too far apart.

To me the Apex is there just to show me anything significant going on and I really only referenced it as it has been consistent (unless I fowl it with something in which case it can freak out for hours) and it does align with the calibrated refractometer (which rarely loses calibration). The concern is more the significant difference in values as I believe certain biological functions start to change as we approach 40ppt (I'll have to go re-watch one of Holmes-Farley MACNA presentations to recall the details!) so I want to be a little mindful of that.

 

[offtropic]

Apologies on my last post...it was Dr. Tim (Hovanec) and not Holmes-Farley that talked about nitrifying bacteria and how the nitrite consuming bacteria stopped functioning well as salt concentration approaches 40ppt. With the 4pt spread between testers this becomes a possibility.