I'm doing an experiment where I have to add a certain concentration of a subtance to water. An example would be that I have to add 1 mg/L of this substance to 5 gallons of water. However, this substance is a liquid and so I don't know what the best way to measure it would be. mg does not seem to be a good option, as the amounts I will be using are relatively small.
Can I convert this to microliters/L or something like that where I could actually measure volume instead of weight?
Any recommendations?