It works good and you can control how much cooling you want by adding a second tube in a bigger container and or use longer tube.

Anyway get are roll of air tubing and put it a container can be anything from a ice cream tub to a drum and have each end sticking out, fill it with water and freeze it, connect it to an aerator and throw the stones in the cloner the cool air cools the water, have a spare and change over when needed, the more tube in the coil the cooler the air.

Hope it helps someone out.