Hey Guys, I am looking for some help here. My situation is I have a 120g geo storage tank, a 60,000btu water to water geo unit and a 16gpm circulator in between. I need to drop the temperature of the tank 40 degrees F. What I need to know how long will it take to cool that down. What I'm actually looking for is an equation or formula to figure this out. With an explanation if possible. Thank you in advance for any help.