The answer to 'water line slow draining' is that a slow draining water line is usually caused by a blockage or buildup in the pipe. This can be due to things like hair, soap scum, mineral deposits, or even tree roots growing into the pipe. Symptoms include water draining slowly, gurgling sounds, or water backing up in the sink or bathtub.
In many cases, you can try to clear the blockage yourself using a plunger, a drain snake, or a chemical drain cleaner. However, if the problem persists or you're not comfortable doing it yourself, it's best to call a professional plumber. They have the right tools and expertise to properly diagnose and fix the issue, whether it's a simple clog or a more serious problem with the water line.