Help with refractometer

[rob92]

I got a portable refractometer today and I got it home, calibrated it to 1.00 or 0ppm with the ultra pure water it came with and with bottled ro water. Well when I went to test my tank it showed that my salinity was at 1.029 and I tested it with my hydrometer and that said it was at 1.024. I recalibrated the refractometer to make sure and got the same 1.029 when I tested the tank. I added water to the tank and the level went down to 1.026 but the hydrometer showed 1.020. Which one should I go by.

 

[rob92]

Or am I doing something wrong

 

[Reefing Madness]

Hydrometer is not accurate, this has been shown over and over. Throw it away. Use the Refactometer.

 

[rob92]

Well I was just wondering since there is such a huge difference so since the hydrometer was low and the refractometer was high. So I can deff tell I've been using way too much salt. I was using 1/2 cup per gallon and the salinity was always below 1.020 so I would add more. Lol glad I finally got the refractometer

 

[Usctom]

It is also much more accurate to calibrate with 35ppt solution. I wouldnt throw out your hydrometer. Just make new corrected marks.

 

[redfishbluefish]

It is also much more accurate to calibrate with 35ppt solution. I wouldnt throw out your hydrometer. Just make new corrected marks.

+1 Calibrate with 53.0 mS calibration fluid.. ....not RO water