Hydrometer Vs Refractometer H2H!

I just received my refractometer from Bulk Reef Supply. Great instrument! Very robust and an overall quality tool. Cant say the same for my instant ocean hydrometer. The needle sticks sometimes, if a bubble attaches itself to the arm, then the results are skewed. plastic and cheap. simple as that.

Just tested my water head to head with both instruments and heres my results...

Hydro

Refracto(the line between the blue and white is the sg)


To my surprise the 2 were remarkably close. only off by .01-ish maybe .02 from all the hootin' and hollerin' ppl do about hydros' and how off they are, maybe there's some reliability that these aren't getting. I know the results from this "test" don't prove or disprove anything. for it to be a real test we would have to increase the sample group. ie more water testing, different temp conditions. Mine by the way are... water is at 78, and the room temp is about 74 give or take.

I guess, in my case, i got lucky. My swing arm hydro has been pretty true to the salinity of my water, but I'm never going to use it again. The refractometer is was simpler to use, compact, and lets face it its pretty neat looking lol.
(ps it took a while to get a picture of the readout on the refracto' with my iphone) but i sware those are my samples, i didnt Google images of these.

 

Great thread! I really need to get myself a refractometer.

 

I too have both and have tested both from time to time and they both are always very close to each other. To be honest, I usually just use my hydro because for me, I find it much easier than the refractometer. The only time I've really used it over the hydro was when I have a fish in a QT tank doing hyposailinity.

 

just be sure to use calibration fluid to set the refrato, ro water is not a good cal fluid to set it with, it does make a difference.

 

For sure

 

I believe bulk reef supply pushes this same fact and actually supplies free bottle of calibration fluid.

Sent from my DROIDX using Tapatalk

 

They certainly do.

 

Just be sure to occassionally soak your hydrometer in a mild vinegar solution, especially if you are rinsing it with tap water. I use both, particularly my Refrac when testing new salt water I have made from my RO water.

 

I've been using my seatest box hydrometers now for almost 19 yrs so I don't figure on switching anytime soon.
I have them calibrated against my Fisher Scientific certified calibrated hydrometer about once or twice a year and clean them once a week in vinegar overnight. They are always on.
I can also use my Fisher hydrometer to check Refractometers for other hobbyists around me.

 

I just purchased my first refractometer from BRS. My SG on the hydro I have been using for the past 2 years reads 1.025. The refractometer reads 1.030 !!! I must say I have to believe the refracto and am in the process Of lowering my SG now. I have read numerous reviews about how the refracto's are inaccurate, give false readings, etc, etc. I have been wanting one for a while now, and finally cracked and bought one. Very easy to use. BRS DOES include calibration fluid. I know there is a huge debate over this, but I will be setting my tank to the refracto from here on out.