Does increased water pressure in a hose affect freezing point?

The freezing point decreases slightly with increased pressure. See the phase graph at the related link.

I do remember seeing a science fair project, where the student attached a weight to a fishing line or dental floss. Then he put it over a piece of ice. The weight, distributed over the small surface area of the string caused high pressure on the ice, which lowered the freezing point enough that the ice melted. As soon as the ice melted, the weight would pull the string down through the water, so then the water no longer had the high pressure on it, and it would freeze again. After several minutes, he picked it up, and the string ran right through the center of the ice cube.