refratometer results

[fishguyxd]

I did a water topoff yesterday and tests today with my new refract. and got 1.029 and then a test with a hydrometer it was on 1.024 Wow a big difference (temp of tank was 80.1F)

I can't remember the formula to correct the hydrometer results vs temp to confirm the refractometer is correct anyone help on the results?

[Matt]

If I can remember this right, most Hydrometers are calibrated for 60 degrees f. Cold water has a higher density than warm water, and that works out to ~.001 difference per 10df.

[Funky_Fish14]

The refractometer I believe likely comes calibrated to 70 degrees F. You should be able to recalibrate it yourself to the temperature of your choice. I'd be checking the hydrometer against the refractometer, rather than the refract against the hydrometer.

Chris

[StirCrazy]

most of the refractometers we use are tempature compensated. it should say in your book. all 3 of my hydrometers are calabrated to 60 degrees which I keep forgetting so I guess I need to add 0.002 to my hydrometer reading.

Steve

[fishguyxd]

So in anyones opion do these results sound bad? I did bring the sality down now, but just throwing the question out there. they say the refractmeter is calibrated to 15 C.

[Matt]

So, your refrac and hydro are both calibrated to 60df. Your refrac says 1.029 at 80df. That (compensated) is 1.031... assuming my math is right, and your refrac is calibrated correctly.