calibrating refractometer

[silverking]

directions say to use distilled water... can I use ro/di?

[arts007]

You can use RODI water, or better a calibrated solution that is 35 ppt, or use table salt-- here is a good article on that http://reefkeeping.com/issues/2004-06/rhf/index.php

[silverking]

thank you

[mg426]

You can also get Pinpoints calibration solution from www.premiumaquatics.com