it only glows under ultraviolet light. best way to tell bring a test guy with yah and wait for him to trip
check it, get some litmus paper from a hardware store. the ph lvel of lsd is roundabout 3.5 .the ph of most tap water is round about 7.0. huge difference in terms of ph. so with an ultra violet light and a lil peice of litmus paper and a lil faith ya almost cant go wrong