Cleaning solution for refractometer

Freewilley

So I got mine today...Youtube video says to use a solution and cloth.

I used google but did not come up with what type of solution to use with electrolyte.
Any idea?

Also, I found that I cannot read the scale as I have to take my glasses off to use the eyepiece. My son read it for me, so basically it is just a check on my hydrometer. It matched the number on my hydrometer.

MichaelK

I've used one before for determining saline concentration, and I always used pure distilled water to clean it.  What is your standardization fluid?  If its water, I'd clean it with distilled water.  The refractive surface needs protection.  I'd wipe it only with lens cleaning cloth.