I worked at an ice arena back in high school. We were a multi-use facility with two rinks. We had an insulated floor that we'd lay down over the ice for non-skating events. I helped one weekend when we had to cut the ice down to nothing to repair leaks (we used red glycol so leaks were readily visible under the ice). It was a lot if work putting the ice back down. We sprayed a standard fire hose nozzle high into the air so the water would shed heat as it fell and thus, would freeze quicker once it hit the glycol coils that were bedded into sand under the ice. This process takes hours. Plus, after a certain point you start taking cuts with the Zamboni to ensure a proper, flat, smooth, finish. Plus, we had to repaint all of the lines after we repaired things. That was in 1978.