Refractometer calibration standard issue

[Nickp]

Hey all.

Currently setting up a small reef after a long break from the hobby, and I've decided to try and do things better this time around .

To that end, I decided to pick up some fritz calibration fluid for my refractometer, followed the instructions and calibrated to 35ppt, then I decided to look in the bottle (don't ask me why) and noticed it had stringy/snotty bits floating in it, which doesn't seem right to me.

Pulled out my scales and made up a solution of 3.65g of sodium chloride and 96.35g of water as per @Randy Holmes-Farley recipe and this is reading 25ppt, so which do I believe?? I'm more inclined to agree with my solution as I know it's fresh and exact, but I now remember why I hated calibrating stuff.

Sorry for rambling lol

 

[Saltyreef]

Hey all.

Currently setting up a small reef after a long break from the hobby, and I've decided to try and do things better this time around .

To that end, I decided to pick up some fritz calibration fluid for my refractometer, followed the instructions and calibrated to 35ppt, then I decided to look in the bottle (don't ask me why) and noticed it had stringy/snotty bits floating in it, which doesn't seem right to me.

Pulled out my scales and made up a solution of 3.65g of sodium chloride and 96.35g of water as per @Randy Holmes-Farley recipe and this is reading 25ppt, so which do I believe?? I'm more inclined to agree with my solution as I know it's fresh and exact, but I now remember why I hated calibrating stuff.

Sorry for rambling lol

Yep i would trust the fresh stuff.

Though snotty fluid is quite common....

I use the tropic marin glass hydrometer myself. One less meter i need to calibrate lol

 

[X-37B]

This is one reason I use the TM floater.

 

[Nickp]

Thanks. Yeah, I hate calibrating stuff, always end up doubting the standard or something else.

I've always been told the floaty type hydrometers were not very good.