[DJ88]

George,

You can either go out and get a $$$$$$ refractometer, that once you buy it you can find out how close or far off your deep six is and use the deep six due to simplicity. Another option is you can get a $20 floating lab grade like I did. J&L carries these ones. It turns out my Deep six is 1 point off and that was all.

As long as you always test with the same one and keep the numbers the same you should be ok. unless your hydrometer is REALLY out of whack.