To treat water that smells, you first have to discover what’s causing the odor. It may be something in the raw water, or something inside the house. The best time to check is after you’ve been away for a few hours. Start by running the water at a faucet outside, where there’s raw, unfiltered water. A slight musty smell can often be removed by a carbon filter. If you encounter a strong, rotten-egg smell, this probably means there’s decaying material underground. A whole-house filter that’s designed to remove hydrogen sulfide is one solution. If the outside water smelled fine, go to a cold, treated water faucet in the house. After it runs a moment, smell the water. An odor here, with none outdoors, indicates a device in the water line needs to be sanitized. Check your water softener, and all water filters, taking the appropriate steps. If the cold water didn’t smell, turn the hot water on. When hot water smells, this is often caused by a corroded anode in your water heater. The anode will have to be replaced, and bleach added. For more information on treating water that smells, contact a water conditioning company.