What kind of water is best to put in the balloons?

The best kind of water is plain, unsoftened and tap water. 

If your home has softened water, which can make globe ice lanterns cloudy, try the cold water tap in the laundry area as it is sometimes unsoftened. An outdoor hose tap will also be unsoftened. Ask a nice neighbor who has unsoftened water or ask if you can fill them at work.

If all else fails, try this: Using your water faucet, fill a Wintercraft Globe Ice Lantern Balloon as full as you intend. Empty the water so you have a stretched out balloon that can take more water for the next step. With a funnel, fill the balloon with distilled or purified water until it starts to come out the top of the balloon. Then put the balloon back on your faucet head and fill the balloon the rest of the way using the pressure of the tap. Because pure water freezes first, the small amount of distilled or purified water will freeze first and most of your softened water will be flushed away when you open the globe.