The answer to 'why is my pipe rusty water' is that rusty water is usually caused by corrosion in the pipes or water heater. This can happen when the pipes are made of iron or steel, which can rust over time, especially in areas with hard water or acidic water. Rusty water can also be a sign of old, deteriorating plumbing that needs to be replaced.
Some common symptoms of rusty water include reddish-brown stains in sinks, bathtubs, and toilets, as well as a metallic taste or odor in the water. If the problem is isolated to a specific faucet or fixture, it may be a localized issue that can be fixed by replacing the fixture or flushing the line. However, if the rusty water is coming from multiple taps throughout the home, it's likely a more widespread plumbing problem that will require professional assistance.