calibrating a refractometer question

[bigford84]

so i just got my first refractometer today 40.00 cause the guy at lfs said someone bought it and brought it back next day. so i would like to make sure it is in good working order. guy at lfs said to calibrate with distled water,drop a few drops on lense and it should read 1.000 or 0, i wanna know if the line between white and blue should rest on 1.00 or 0? or just be all blue??

left pic is no water... rite pic is my tank water=1.025

 

[Kurt_Nelson]

If you put distilled water on it, it should look like your right-side picture but the "line" is at 1.000/0.0

However... to really get a more accurate calibration you should get yourself some Pinpoint conductivity calibration solution. That will calibrate it at 35ppt, or a little over 1.026. Some refractometers will be just fine calibrating with distilled water, others will be off a couple points (.002) when you get up in to the 1.025 range if you used distilled water.