Reading Salinity

[Randy Holmes-Farley Verified Community Expert]

I don't get all of the hand-wringing, uncertainty and expense people go through, when this simple tool is virtually flawless, requires no maintenance and has a maximum deviation of about 0.001 at 77 degrees F.

I can explain why I didn't use it despite having one, IMO.

My conductivity meter was quicker to use, also read the temp, was perfect for acclimation, never drifted, and could read the potency of other materials I used (such as kalkwasser).

 

[schooncw]

But it aint digital!!! Jokes aside, yes valid point, but personally I had these tools already.

You listed an Instant Ocean Hydrometer. I have one of those, as well as a digital pen but I found them lacking, when compared to the floater.

 

[Reefer1978]

You listed an Instant Ocean Hydrometer. I have one of those, as well as a digital pen but I found them lacking, when compared to the floater.

No argument there, but I have it, thus I listed it as a data source. Was kinda hard to resist getting it for $1.99.

 

[WvAquatics]

@Randy Holmes-Farley i looked up your mixing ration for refractometer. Could you cut the weight of salt and water in half I don't need 2l worth of solution

 

[Randy Holmes-Farley Verified Community Expert]

@Randy Holmes-Farley i looked up your mixing ration for refractometer. Could you cut the weight of salt and water in half I don't need 2l worth of solution

Sure. It can be scaled to any volume.

 

[Reefer1978]

@Randy Holmes-Farley i looked up your mixing ration for refractometer. Could you cut the weight of salt and water in half I don't need 2l worth of solution

I will assume the answer will be: unless you use higher precision measuring equipment, go with higher volume to get precision from the volume.

 

[Reefer1978]

Sure. It can be scaled to any volume.

Or what Randy said :-) My prediction was incorrect.

 

[Randy Holmes-Farley Verified Community Expert]

Or what Randy said :) My prediction was incorrect.

It is true that if you scale it beyond what you can accurately measure, it will lose accuracy. :)

 

[WvAquatics]

Ok I actually noticed the 221ml formula above the 2l so that's not bad to make and dump. Great help my refractometer was off around 7ppm. So tank was 28ppm this am will slowly being it up over next few days.

 

[geologeek]

Sorry for the slight hijack of your thread, but @Randy Holmes-Farley is it ok to make calibration fluids using table salt with sodium ferrocyanide as the anti caking agent?

Mortons iodised salt is not something easily found in the UK and our table salt generally contains salt and sodium ferrocyanide.

 

[Randy Holmes-Farley Verified Community Expert]

Sorry for the slight hijack of your thread, but @Randy Holmes-Farley is it ok to make calibration fluids using table salt with sodium ferrocyanide as the anti caking agent?

Mortons iodised salt is not something easily found in the UK and our table salt generally contains salt and sodium ferrocyanide.

Weight based recipes will hardly be impacted by traces of additives. Volume based recipes may be impacted somewhat by particle size distribution, more than minor additives.

 

[geologeek]

Weight based recipes will hardly be impacted by traces of additives. Volume based recipes may be impacted somewhat by particle size distribution, more than minor additives.

Thank you!

I'll crack out the scales and salt in the morning and see how bad my refractometer has gotten.......

I did make a solution with salt, which turned out to be sea salt and the refractometer read 35ppt and zero with RODI. But I will see what it says with a table salt solution.

My TM refractometer should hopefully arrive tomorrow and I wanted to just give it a check with a calibration solution just to have complete trust in it and that the scale hadn't slipped in transit from being shaken and thrown by the postal service because of the fragile sticker that will be on the box.

 

[rishma]

I can explain why I didn't use it despite having one, IMO.

My conductivity meter was quicker to use, also read the temp, was perfect for acclimation, never drifted, and could read the potency of other materials I used (such as kalkwasser).

I miss having a conductivity meter, I used it for Kalk too. Very useful tool but not cheap. After my second pinpoint brand meter died I didn’t buy another one.

 

[Reefer1978]

Quick update, ICP came back, Vertex Refractometer was spot on.

 

[charleydavis]

Calibration solution is fresh. For RO, Milwaukee reads 0. Refractometers dwarf higher as they are calibrated with 1.026, and of course if I calibrate with 0, they read salinity lower.


Agree, but do I really need more equipment for such a silly thing?


Confirmed, you are of no help! Just kidding Mojo, thanks for jumping into the thread.

What does "Refractometers dwarf higher...." mean? Sorry I don't understand.