By Today's ParentUpdated Jul 24, 2017
1) Remove the label from a 2-L pop bottle. Push the sharp end of the knife into the side of the bottle until it makes a tiny hole. Continue poking holes across one half of one side of the area where the label was. Ensure the bottle is still inflated.
2) Secure a garden hose to the opening of the bottle with duct tape. Wrap the tape tightly around the hose to make sure it doesn't leak.
3) Turn the water on. The greater the water pressure, the higher the spray!