preventing coolant evaporation

[cropwell]

I am damn glad my coolant evaporates, but only when it goes all over the floor. I can understand that it is a problem in Bahrain though. As it is water loss, then top it up, otherwise a loose lid will help.

[lucan07]

The balls tend to be used on water located in direct sunlight as they would be wetted by water draining from above this would give a larger area to evaporate from during use, I can see little advantage in this case for using them simply covering tank when not in use should be far more beneficial.