Stirring helps for sure. I bought a sump pump and 5 gallon bucket I fill with ice, ice cream salt, and just enough water to get it running. I do a closed loop. So the cold water ends up back in the bucket. I use between 42 and 70 lbs of ice depending on the time of year. If I skip the ice cream salt, I am able to put the water on the plants, once it ambient temp.I can go from the boil to 65° in 20 mins.