Please place Orders Online

Email Questions

Technical Support 7 days a week. is a BBB Accredited Water Conditioning Equipment Store in Venice, FL
Knowledge Base:  
You are here: Knowledge Base > General questions - Water Treatment
Stinky - Rotten Egg - Odor
Last Updated: 06/17/2015
Hydrogen sulfide is a gas that causes an obnoxious rotten egg odor in your water.
Most noticeable when water is first turned on ( because the gas separates from the water and collects in the pipes as the water sits ).

If you notice this smell in your water, it probably contains hydrogen sulfide (H2S) gas. Sources of this gas include:

  • Decay of organic matter or chemical reactions with sulfur-containing minerals in soil and rock.
  • Sulfate-reducing bacteria which convert naturally occurring sulfate and other sulfur compounds to hydrogen sulfide gas.
  • Water heaters can produce hydrogen sulfide gas by:
    • Providing a warm environment for sulfate-reducing bacteria to live.
    • The anode, which is usually magnesium, supplies electrons that sustain the reaction of sulfate to hydrogen sulfide gas.

Should hydrogen sulfide gas or sulfur-reducing bacteria concern me?

The hydrogen sulfide gas levels found in well water is not harmful to your health ( but friends and relatives will let you know your house stinks when they walk in the door). There is also the problem of sulfur-reducing bacteria generating ( growing ) a slime that can promote the growth of other bacteria and clog wells and plumbing as thick layers start breaking off from pipes and inside of any tanks.

  • Hydrogen sulfide gas will cause black staining of silverware and plumbing fixtures
  • Will corrode galvanized and copper pipes ( the higher the level of H2S, the faster this will occur ).
  • Also known to corrode the copper coils in central air conditioners and refrigerators.

    How do I determine the source?

    Run water separately from both the cold and hot taps, preferably when you have been away from the house for a few hours so your sense of smell is more keen.

    • If the smell is only from the hot water tap, the source is most likely your water heater.
    • If the smell is from both hot and cold taps, but only from water treated by a water softener, you may have sulfur-reducing bacteria in your water softener.
    • If the smell is from both taps and diminishes after the water runs, you may have sulfur-reducing bacteria in your well or piping.
    • If the smell is from both taps and is persistent, you may have hydrogen sulfide gas in your groundwater

    How can I eliminate hydrogen sulfide gas?

    If the source is hydrogen sulfide gas in the groundwater the water may be treated by:

    • Activated carbon filters for hydrogen sulfide concentrations less than 1 mg/L.
    • Manganese greensand filters for hydrogen sulfide concentrations up to 6 mg/L.
    • Oxidation filtration systems ( Aerator ) for hydrogen sulfide concentrations of any level up to 5mg/L. ( high levels require adding chlorination and carbon filtration).
    • Chlorine injection system with 120 gallon contact tank and 1 ( or 1.5 ) cu.ft. Carbon Tank with backwashing valve after ward, and the problem is less then 3 mg/l ( ppm ).

  • The proper size equipment, levels of chemicals, and frequency of cleaning all depend on the amount of H2S in the water and how much water you use on a daily basis. So, the first thing you need to do, before purchasing or adjusting equipment for H2S removal is to get an accurate test of the level in the water.

    This is best done on site after running the source water for about 5 minutes. Professional water treatment dealers have the test kits to accurately measure the levels in your water source, and will often test for free ( of course they will want to sell you some equipment too ), or kits can be purchased online $ 50 - $ 100 is the common price range for a professional kit ).

    *** Low Cost for Low Level Test Kit ( 2 ppm or less )

    Please Rate the Usefulness of this Article


    Related Articles
     > # 1 FAQ = High Water in Brine Tank - Problem -Softener does not remove the water from my salt tank or overflow
     > Links to Other Websites
     > How and Why to use Acid Neutralizing Media Calcite and Corosex ( Magnesium Oxide )
     > No Pressure Unless the Softener is By Passed
     > How a water softener actually works and why does it feel slimy
     > Average Salt Amount Needed and Normal Water Level In Brine Tank
     > Salt Usage In Water Softening
     > No Salt Systems for Water Softening
     > Dishwasher Glassware Etching Cause Explained
     > Air in water lines after Softener Regenerates
     > Common Water Problems
     > ECO - Friendly Alternative to SALT Softeners
     > How do you determine if you actually need a softener?
     > How do you put a softener out of service without damaging it?
     > How Long Until Water Feels Soft Again After Repair
     > Hydrogen Sulfide levels affected by amount of water used and the ground water table
     > Will a Water Softener remove the iron from my water?
     > Iron Staining and my Water Softener seems to be working okay, Why is that?
     > Odor - Sulfur (Hydrogen Sulfide) in your water
     > I have a Water Softener, but I still have odor in my water. Why is that?
     > Orange Sand Coming Into House
     > Salty Water Taste in the Morning
     > High Water in Brine Tank - Problems and Solutions
     > Sodium in the Water Softening
     > What Brine ( Salt ) Setting Amount to Use?
     > Will a Water Softener make my water safe to drink?
     > Stains in Laundry - several possible causes
     > Looking for someone to Service My Water Softner ( Softener ) in my area.
     > Pump Pressure Low or Cycles OFF and ON ( Well Water )
     > Sodium Levels in Water when Softened
     > Air Check inside Brine Tank can becomes Stuck or Water Logged
     > Aerator Use and Cleaning Q & A
     > Air Check - Ball seated or dropping early during the BRINE/SLOW RINSE portion on the 155 or 255 Series Valve
     > Brine Valve Replacement in Salt tank ( with Float Shut Off )
     > UV for Water Purification - Does it Work?
     > Why Gravel is Not Needed in Residential Size Water Softener
     > Frequency of Regeneration - How Often Should Softener Recharge?
     > Fittings Measurements Different Then Expected ( 1/4 and 3/8 fittings )
     > Choosing a Resin - What is the Difference
     > Basic Installation Guide for New Water Softener
     > Which is better or cheaper... Powdered Resin Cleaners or Res-Up Liquid?
     > Choosing a Softener System - Which Brand is Best?
     > Sediment filter ahead of the softener - When, Why, and Which one.
     > Brine Tank Assembly - Questions, Answers, Video Link
     > ChemTech and Pulsafeeder chlorine solution pumps
     > Potassium Chloride - Substitute for Salt ( Sodium Chloride )
     > Pressure Drop or Flow Rate reductions through a Water Softener / Filter System - Things to Consider
     > Recommendation of Fleck 5600 Econominder and Hankscraft Equivalent water softener replacement valves - Which Brand is Best?
     > How does Hankscraft metered valve compare with the Fleck 5600 or the Hankscraft digital unit in terms of lasting durability
     > MediaGuard filter on Distributor Tube can cause pressure loss
     > Do I need an Iron Filter?
     > Salty Water Taste - New Valve Installation
     > Motor Identification - How to determine Type and Part Number
     > Irrigation - Iron Removal options