The answer to 'toilet rusty water' is that it is usually caused by corrosion in the toilet tank or plumbing system. Symptoms include reddish-brown water coming from the toilet, staining of the toilet bowl, and a metallic taste or odor in the water. The main solutions are to clean the tank, replace corroded parts, or address the source of the rust in the plumbing.
If the rust is limited to the toilet tank, this is often a DIY fix that homeowners can handle by draining the tank, removing and cleaning the tank components, and replacing any corroded parts. However, if the rust is coming from the main plumbing system, this is a more complex issue that likely requires a professional plumber to diagnose and repair.