[header] How to brix test [title] Add a few drops of distilled water to the view plate. [step] Buy a jug of distilled water, or at least use a basic water filter to get clean water. Open the daylight plate, which is a hinged cover that closes over the angled prism. 
Use an eyedropper or pipette to drop a few drops onto the view plate. [substeps] It's important to use pure water that is clean and free of extra particles.