Softened water has a rotten egg (sulfur) odor

Safety first: Ventilate the area if odor is strong. Do not mix cleaning chemicals (e.g., bleach and acids).

Step-by-step checks:

• 1. Test raw water: Check if the odor is present in water bypassing the softener. If so, the source is the well or municipal supply.
• 2. Sanitize softener: Follow Marlo's procedure to sanitize the resin tank and brine system, typically using a measured amount of household bleach introduced into the brine well and drawn through during regeneration.
• 3. Increase usage or regeneration: Stagnant water can worsen odors. Increase regeneration frequency or flush plumbing regularly.
• 4. Consider sulfur treatment: For persistent hydrogen sulfide, install or service a dedicated Marlo sulfur/odor removal system upstream.

When to replace parts: If odor persists and resin is suspected to be contaminated or degraded, replace the Marlo cation resin media. For severe sulfur, add a Marlo sulfur filter.