There are plenty of methods that you will hear on how to care for a tattoo but based on the shop I work at, the care instructions say that showers are ok for your tattoo because the water is moving whereas in a lake or pool the water is suffocating the skin with no room to breath. As for just using hot water to heal it, you need some kind of lotion. Some of the best stuff in MY opinion is Aquafor lotion. But any nonscented lotion works.