Jestersix

Please recommend a good brand of refractomer

Vincerama2

Vincerama2

Supporting Member
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My old refractometer's hinge broke, making it a bit of a pain to use (the plastic lens thing that flips up and down is detached) so I ordered a new one from Amazon.
I was testing my tank water and it showed quite high. So I started to make up new water, then decided to check the new (factory calibrated) refractometer. It claims to be "automatic temperature calibrated/compensated"
Well, using RODI as 0, I set both refractometers to 0. Then using a small bottle of "Salinity reference 1.025" water than I got at a BAR frag swap ... who knows when, I checked both refractometers. The old one showed exactly 1.025, the new one I got was showing 1.028. It doesn't seem like much, but we need 0.001 precision here. So I set calibrated the new refractometer to 1.025 and then tested again with RODI and sure enough the line shows below zero.

Now, Calibrating at 1.025 should give me enough precision around 1.025, but ... why should I when I know refractometers should be able to calibrate at zero and 1.025 with much better precision and accuracy, given the performance of my old refractometer, so I'll try to send this one back to Amazon.

My old one has no brand markings so I have no idea what brand it is.

Do you guys have a known good brand that can give me accuracy at zero and 1.025?

Thanks!

V
 
I use the Hanna salinity checker. It floats, it tells the temp and uses that to adjust the salinity reading, and it gives a result in just a few seconds.

I dunk mine in the ATO res then wipe it off to keep it from having salt build up. I calibrate it every month or so. I never had a regular refractometer so I can’t compare, but I think this has to be easier.
 
I bought the generic ATC one from Amazon years ago and it's still solid and haven't fallen out of calibration....so as long as you remember to make sure the hinge swings smoothly. That affects the reading significantly
 
max_nano said:
I use the Hanna salinity checker. It floats, it tells the temp and uses that to adjust the salinity reading, and it gives a result in just a few seconds.

I dunk mine in the ATO res then wipe it off to keep it from having salt build up. I calibrate it every month or so. I never had a regular refractometer so I can’t compare, but I think this has to be easier.
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Good to know. I'll definitely be picking up one of these now.
 
NanoCrazed said:
I bought the generic ATC one from Amazon years ago and it's still solid and haven't fallen out of calibration....so as long as you remember to make sure the hinge swings smoothly. That affects the reading significantly
Click to expand...
That's the one I'm returning. I think ATC just means Automatic Temperature Compensation.
 
max_nano said:
I use the Hanna salinity checker. It floats, it tells the temp and uses that to adjust the salinity reading, and it gives a result in just a few seconds.

I dunk mine in the ATO res then wipe it off to keep it from having salt build up. I calibrate it every month or so. I never had a regular refractometer so I can’t compare, but I think this has to be easier.
Click to expand...

I had no idea this thing floats!!!
 
Meshmez said:
Im not sure why, but most refractometers i have seen say NOT to calibrate to zero.
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The instructions that came with the refractometer say to calibrate to zero. But in googling around, I'm seeing some recommendations that are the same .. use 35ppt calibration fluid instead .. ?

Not sure which is correct. I'm wondering now if it doesn't matter what refractometer I get, they'll all be off at zero and 35ppt OR maybe my RO/DI water is not quite zero, though the error shows my RO/DI as being BELOW zero, which makes no sense. Plus the old refractometer was dead on at zero for RODI and 1.025 for the calibration fluid.
 
Went through 3 of those 15$ refractometers and I highly recommend snagging the hanna salinity probe instead of throwing money down a pit which is what those things are imo. Never calibrated it in almost a year and always checks out to my Milwaukee salinity checker.
 
My Hannah measurements drifted over time and caused me to have issues with high salinity in my first tank. Even after calibration it is not correct. I then tried a cheap refractometer from Amazon and that was terrible.

So, now I use a Red Sea refractometer and the Milwaukee. The Hannah sits in a drawer. Wouldn’t recommend.
 
Meshmez said:
It's expensive, but I picked up the Milwaukee digital refractometer and I have been very happy with it.
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Same. I have learned that the first bit of water put on the reader should just be wiped off, then a new sample put on. I think there is always a bit of salt residue left on it. If I do t do this my first reading will always be high.
 
I did an experiment with the club last year during a talk about refractive test.

I had as many people as possible bring their own refractometers and their calibration solutions. Everyone calibrated with their own calibration solutions. Then tested a sample water. Results were all over the place.

The 2 Milwaukee (1 being my own) was consistently 0.001 sg higher than everyone else. We calibrated with RO then with Milwaukee’s own solution. Same result.

IMO, it really doesn’t matter if your water is ( in reality) at 1.026 or 1.025 or 1.027 as long as it stays the same all the time. Stability is key.




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