Rotten-egg smell
Why does my well water smell like rotten eggs?
Hydrogen sulfide gas, usually worse on the hot side, comes from sulfate-reducing bacteria or sulfur in the formation.
How you notice it
- Rotten-egg smell, strongest on hot water
- Tarnished silverware and brass
- Smell returns days after bleaching the well
Why it happens
Sulfate-reducing bacteria in the well or the water heater convert sulfate to hydrogen sulfide gas. Deep bedrock wells are the usual setting.
The fix
- Air-injection oxidation sized for sulfide, not just iron
- Replace a magnesium water heater anode with aluminium if the smell is hot-side only
- Shock-chlorinate the well and lines before judging results
Equipment that solves it
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SpringWell WS1 Air-Injection Iron & Manganese Filter
Oxidizes dissolved iron and manganese, then filters it out — no chemical feed, no staining.
$60 USD/yr consumables · standard
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US Water Systems Matrixx Infusion Iron & Sulfur System
For carbonate and sandstone wells with heavy iron plus rotten-egg sulfur odour on the hot side.
$90 USD/yr consumables · premium
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iSpring F4WGB22BM 4-Pack 20″ Replacement Filter Set (for WGB22BM)
Complete 4-cartridge 20″×4.5″ replacement pack (2× sediment/carbon, 2× iron/manganese reducing) for 2-stage WGB22BM systems.
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Max Water Iron & Manganese 3-Cartridge Replacement Set (10″×2.5″)
Three-cartridge 10″×2.5″ replacement set for standard slim housings — sediment, iron/manganese reduction, and carbon stages.
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PUREPLUS RFN10BB-SZ Iron & Manganese Cartridge (10″×4.5″)
Big Blue cartridge (10″×4.5″) for dissolved iron and manganese reduction in standard 10-inch housings — fixes rust staining at the source.
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iSpring WGB32BM 3-Stage Whole House Filter (20″ Big Blue)
20″ Big Blue 3-stage POE: sediment, CTO carbon, and catalytic iron/manganese media. Bridges the gap when iron staining is active but full air-injection is overkill.
Check price on AmazonWorks with: 4.5″ × 20″ Refillable KDF 85 + KDF 55 + Carbon Cartridge
Refills & maintenance
iSpring FM25B 20″×4.5″ Iron & Manganese Cartridge (for WGB32BM)
iSpring F3WGB32BM 3-Stage 20″ Replacement Filter Set
iSpring FM25B 20″×4.5″ Iron & Manganese Cartridge (for WGB32BM)
High-capacity 20″×4.5″ catalytic media cartridge for the iSpring WGB32BM. Treats iron up to 3.0 ppm and manganese up to 1.0 ppm on moderate staining wells.
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iSpring F3WGB32BM 3-Stage 20″ Replacement Filter Set
Complete 3-cartridge 20″×4.5″ replacement set (sediment, CTO carbon, and iron/manganese) for the iSpring WGB32BM.
Check price on AmazonPentair Pentek 150468 Big Blue 20″ Filter Housing (3/4″ Ports)
Whole-house DIY Big Blue housing for sediment and iron filtration, with 3/4″ ports. Fits standard 20″ × 4.5″ cartridges.
Check price on AmazonWorks with: 4.5″ × 20″ Refillable KDF 85 + KDF 55 + Carbon Cartridge, iSpring WGB32BM 3-Stage Whole House Filter (20″ Big Blue)
Refills & maintenance
4.5″ × 20″ Refillable KDF 85 + KDF 55 + Carbon Cartridge
4.5″ × 20″ Refillable KDF 85 + KDF 55 + Carbon Cartridge
Refillable KDF 85, KDF 55, and carbon cartridge for sulfur smell and iron, made for 20″ Big Blue housings.
Check price on AmazonWorks with: Pentair Pentek 150468 Big Blue 20″ Filter Housing (3/4″ Ports), iSpring WGB32BM 3-Stage Whole House Filter (20″ Big Blue)
Frequently asked questions
Why does my well water smell like rotten eggs?
Hydrogen sulfide gas, usually worse on the hot side, comes from sulfate-reducing bacteria or sulfur in the formation. Sulfate-reducing bacteria in the well or the water heater convert sulfate to hydrogen sulfide gas. Deep bedrock wells are the usual setting.
How do I know if I have rotten-egg smell?
Common signs include: Rotten-egg smell, strongest on hot water; Tarnished silverware and brass; Smell returns days after bleaching the well. Confirm with an accredited lab before buying treatment gear.
What is the fix for rotten-egg smell?
Air-injection oxidation sized for sulfide, not just iron Replace a magnesium water heater anode with aluminium if the smell is hot-side only Shock-chlorinate the well and lines before judging results
Should I treat the whole house or just drinking water?
Staining, scale, and bacteria risks are usually whole-home issues. Taste, dissolved solids, and some metals can be finished at a kitchen RO tap after the main train is correct.
How do I match this problem to my municipality?
Open the provincial directory and the municipality page if one is published. This guide does not list places from a hardness or depth model.
Related tools
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