salinity question

[fishykisses]

i got my refractometer in the mail last week and tried it out today.
Big difference and i'm wondering if i calibrated correctly or if there really is that big a difference between the hydrometer and the refractometer.
Hydrometer reads 1.027, Refractometer reads 1.023.
I think i may take a sample to my LFS and get them to test and see. that seems like an huge difference!
has anyone else had this kind of experience?