Which calibration fluid is right?

[turbo2oh]

I just tested my Bulk Reef Supply refracto juice which should be 35 PPT against my Hanna instruments 35 PPT calibration solution and I’m getting drastically different readings am I missing something or is one of these way off? Neither are expired, both at room temp. It’s not even close one is reading 30 and one is reading 35.

Do I need to buy a hydrometer to get a source of truth?

 

[turbo2oh]

The reason I’m even trying this is my refractometer and digital Hana salinity tester are getting different readings despite having calibrated them both with their respective solutions.

 

[GSPClown94]

Throw both of those in the trash and follow this to make your own DIY standards https://www.reef2reef.com/ams/reef-aquarium-salinity-diy-calibration-standards.956/

 

[dedragon]

either the one from randy or use a tropic marin glass hydrometer to calibrate or just use it alone

 

[NanoSteam]

I can say for certain after trying all the Hannah calibration fluids that came with my tester they were all wrong. Tested against Randy's recipe and multiple other fluids I ordered as well as against the TM glass Hydrometer.

 

[slingfox]

I went through three Hanna salinity checkers, each calibrated with the Hanna solution. These checkers are not reliable.

 

[NanoSteam]

I went through three Hanna salinity checkers, each calibrated with the Hanna solution. These checkers are not reliable.

Agreed, and seems to be the consensus with anyone I've seen who has tried testing with a different device.

 

[BriDroid]

Randy’s recipe is the way to go. My refractometer always matches my ICP results. Cheap and super easy to make!

 

[NanoSteam]

Randy’s recipe is the way to go. My refractometer always matches my ICP results. Cheap and super easy to make!

Yup! I would also invest in a food scale that does decimals. Makes it that much easier and accurate. I had to do a little guestimating the first time since my scale didn't have that much resolution

 

[BriDroid]

Randy’s recipe is the way to go. My refractometer always matches my ICP results. Cheap and super easy to make!

Yup! I would also invest in a food scale that does decimals. Makes it that much easier and accurate. I had to do a little guestimating the first time since my scale didn't have that much resolution

They’re cheap on Amazon and come in handy for all the DIY solutions.

 

[painter1982]

I made up some of Randy’s formula with RO/DI and table salt and tested it against BRS solution. Both are the same 35ppt when tested.

 

[slingfox]

I made up some of Randy’s formula with RO/DI and table salt and tested it against BRS solution. Both are the same 35ppt when tested.

What does the Hanna read for the DIY calibration solution?

 

[NanoSteam]

What does the Hanna read for the DIY calibration solution?

This!

If it reads correctly at 35PPT just calibrate it with Randy's solution and I would consider it useable at that point. Of course verify with other tools here and there.

 

[Randy Holmes-Farley Verified Community Expert]

I have a suspicion that based on other threads that the Hanna may be too low. The BRS also has a poor reputation.

Which fluid is lower?

As others note, making your own is a good plan.

 

[turbo2oh]

@Randy Holmes-Farley I mixed the two different calibration solutions for conductivity and the refractometer and calibrated both with their respective solutions. They’re much more closely aligned now. I’m still not clear on why they should give the same reading for tank sample when the calibration solutions are mixed a different ratios but maybe I need to reread the article again.

 

[Randy Holmes-Farley Verified Community Expert]

@Randy Holmes-Farley I mixed the two different calibration solutions for conductivity and the refractometer and calibrated both with their respective solutions. They’re much more closely aligned now. I’m still not clear on why they should give the same reading for tank sample when the calibration solutions are mixed a different ratios but maybe I need to reread the article again.

Here’s the short answer. My diy standards are not seawater, so cannot match all of the properties of 35 ppt seawater (conductivity, refractive index and density) at the same time. But they can perfectly match one at a time, so can work for one device type at a time.

 

[turbo2oh]

That does make sense. Thanks.

 

[Luke Schnabel]

I've had so many bad Bulk Reef Supply refracto juices that I threw them away. I only use a Hydrometer and a refractometer (that is calibrated with the hydrometer)