Refractormeter Calibration?

[MizTanks]

What is the best way to calibrate my refractormeter without using the calibration fluid, as I don't have any?

[jduck]

I would recomend ordering some calibration fluid will cost about $15 from amazon, or you can get it from one of the site sponsors. Calibrating with RO water can cause it to be off as much as .004

Refractometer Calibration: the Myth and Risks of using RO/DI Water - Reef Central Online Community (http://www.reefcentral.com/forums//showthread.php?t=1963296)