Refractometer

[JHG]

So to calibrate the refractometer I should put a few drops of the distilled water on the glass? Forgive me, just want to get this right.

[Railskinner]

that is correct , then adjust till everything is at ZERO

[JHG]

So when using the refactometer one only puts a few drops of the tank water on the glass as well; unlike when you use a pH meter?

[prosnow]

yup, exactly

[JHG]

Thanks.