JACKS MAGIC TOPICAL STAIN TEST KIT (STAIN ID KIT) is the first step in performing a successful Jack’s Magic stain removal. The Stain ID Kit is designed to take the guesswork out of removing swimming pool stains. One of the (4) simple topical tests will identify what bests removes a swimming pool stain, saving both time and money. >LI>Please Note: The water should be at least 65-70 degrees in order to ensure accurate testing results.