RULE 1 - KISS - Keep It Sanitary, Silly! Most malfunctions are caused by a dirty airbrush. With airbrushes, cleanliness is next to godliness. If you use water based paints use distilled water or purified water from one of those machines.  You won't get any mineral deposits in your airbrush & the colors of whatever medium you use won't be affected by chlorine, minerals or anything else your tap water contains. This is RULE 1 for a reason!