How often do you calibrate your refractometer?

[ZaneTer]

Every single time I use it

 

[balajeek15]

Its time for me to buy a good salinity checker and after reading this forum I am not sure if i should go with Hanna or Vee Gee Scientific.

Hanna as per their instruction its a tester to test fresh mix salt water and not directly on the tank, what!

 

[infinite0180]

Its time for me to buy a good salinity checker and after reading this forum I am not sure if i should go with Hanna or Vee Gee Scientific.

Hanna as per their instruction its a tester to test fresh mix salt water and not directly on the tank, what!

My hanna salinity checker works great right in my tank. Matches my calibrated refrac as well as what ATI reported from my last ICP test. I trust it without a doubt...

 

[Fallling]

Currently - never.

The little bolt for adjusting is stuck/rusted. Fortunately, it's stuck right at 35 ppt. Every once in a blue moon I do double check with calibration fluid that it hasn't changed, but it's been like this for 2 years now without any issues (I should really get a new refractometer).

Before this, I calibrated EVERY time- I had some bad experiences by skipping this step.

 

[balajeek15]

Great, just ordered one at amazon for tomorrow delivery, couldn't wait for BRS shipping

 

[Bleigh]

I finally calibrated my refractometer for the first time a few months ago to find that it was pretty far off. Now I make sure to calibrate before every use and find that it often needs small adjustments.

I just had a similar experience. I was mixing my salt about 20% weaker than I should because of it. I've calibrated with 35 ppt solution I got off amazon every time I use it now. It has been a little off each time. It surprises me how little it takes to bump it off.

 

[Tastee]

I only test my salinity every few weeks and just calibrate my refractometer to zero with RODI water before each test. I run an Apex however so rely on it’s probe to alert me to salinity changes - only use it for trends not absolute numbers.

 

[Westside Guy]

I calibrate my Red Sea refractometer almost every time I use it with RO which is what Red Sea recommends. I recently purchased some 35 ppt solution to confirm everything is correct.

 

[X-37B]

Every time I use it. Even if doing my 3 tanks I will calibrate prior to testing each tank.

 

[cvrle1]

Question for folks using various calibration solutions. How much do you trust those to be at 35ppt? Reason I am asking is because I was reading quite a bit lately on this topic (started out by researching how often to calibrate refractometer funny enough) and Randy Holmes-Farley has said on more than one occasion that he found that those calibration solutions can be off. Thats why he shared recipe for his mixture that gives 35ppt every time without any doubt. Great thing about it is that it requires 2 items (salt and RODI water) and it is really easy to make.

DIY Salinity calibration solutions

Randy, In light of another post on calibrating a conductivity meter, I decided to give it all a shot on my own system. I read through your article on DIY salinity calibration (http://www.reefkeeping.com/issues/2004-06/rhf/) and have a few questions for my simple brain. 1. Is the Brand MORTON...

www.reef2reef.com

 

[HOLYREEFER]

Every time I use it. Even if doing my 3 tanks I will calibrate prior to testing each tank.

Ditto