*PLUMBERSSTOCK EXPERT* responded:
Thank you for asking help from the PlumbersStock team. This Dial 5242 Heavy-Duty Descalant is an agent used for cleaning evaporative coolers. In most cases, a certain amount of the cleaner is poured into the evaporative pan with water. It is run on pump mode for about 20 minutes so the scale and minerals will get washed out into the pan. Then, you drain the water, flush it out and refill the pan with clean water. Please be reminded to observe the precautions stated on this Safety Data Sheet to prevent accidents. If you need further instructions, it would be best to call Dial at 1-800-350-3425. Thank you for visiting PlumbersStock.com!