> Date: Sun, 10 Aug 1997 17:56:40 -0400 > From: Bjorn Straube <straube at digital_net> > > I'm going nuts! I need to be able to convert between ppm NO3 and > mg/l NO3. I know I have the formula somewhere, but I'll be darned if > I can find it at the moment. For aquarium purposes: 1000 milligrams = 1 gram 1000 grams of water = 1 liter 1 mg/l = 1 part per (1000 X 1000) parts = 1 part per million George