Another big advantage is that when you make a hockey rink out of synthetic ice you do it once and it's done, you have a great skating surface for years and years. As opposed to waiting each winter for the temperature to fall below freezing, standing out in the cold with a hose and then crossing your fingers that it doesn't warm up and melt.
You can also have your rink set up in places that you would have difficulty putting it if it wasn't made of synthetic ice such as the basement or garage. Synthetic ice typically comes in panels that easily fit together like a jigsaw puzzle so you can put it together yourself and move it if you like too. As long as you have a flat and stable surface you'll have a hockey rink that performs very much like real ice. All things considered when you add it all up, to make a hockey rink out of synthetic ice just might be the smartest answer to the question of how to make an hockey rink.