Caution for anyone using a refractometer

[Canadian]

Originally Posted by Reefer Rob

Do you warm your refractometer to 25C?

It sits in my stand which contains my HQI ballast and has an ambient temperature around 25C (which, incidentally, makes it a really bad place to store tests kits - hence my Elos kits are kept in the basement which remains relatively cool).

I also do not allow the drops to sit on the refractometer for any length of time before I take my reading - drops on, flip the lid and take the reading for both calibration and when taking tank readings.