anderson FD601 Fluorescent Leak Locating Dye, 8-Ounce Fluorescent leak locating dye has a special concentrated dye that holds together underwater Identify leak as locating dye is for the detection of leaks in light colored pools Works on plaster as well as vinyl and painted pools and can be refilled with leak master dye Plastic needle allows for precise dye placement without creating unwanted currents Comes in fluorescent color; available in 8-ounce pack