Many experts agree that the bacteria that causes these pink stains is most likely Serratia marcescens, a bacteria which is found naturally in soil, food, and in animals. Serratia, which produce a characteristic red pigment, thrive on moisture, dust, and phosphates and need almost nothing to survive.
Why Does My Water Leave a Red Residue? The two most common causes of red residue from water are iron and Serratia marcescens bacteria. Iron contamination occurs when high concentrations of iron get into a home's plumbing system. Conversely, Serratia marcescens bacteria do not usually grow within plumbing pipes.
It is bacteria known as Serratia marcescens, according to Roxanne Johnson, North Dakota State University Extension Service water quality associate. You may find this bacterium in moist areas such as toilet bowls, sinks, tiles, shower stalls, bathtub enclosures and even your pet's water dish.
Hard water stains appear as chalky white residue that results from buildup of excess minerals present in hard water. You might have noticed these unsightly hard water stains building up on your shower doors, faucets, showerheads, and other places where water is used throughout your home.
If you're seeing pink stains in your bathroom, the problem is not usually water quality. Pink stains in bathtubs, toilets, and showers are caused by a bacteria called Serratia marcescens, which is found naturally in the environment. This bacteria is airborne and finds a home on moist surfaces.
Calcium deposits are denser than efflorescence and will usually appear as white streaks running down a material's surface. Because the calcium forms right below a material's surface, water will not affect its appearance.
Once established, the organism usually cannot be eliminated entirely. However, periodic and thorough cleaning of the surfaces where the pink slime occurs, followed by disinfection with chlorine bleach, appears to be the best way to control it.
What is “pink mold,” then? The discoloration comes from a biofilm—that is, a bacterial colony—of Serratia marcescens. The airborne bacterial species thrives in moist environments like showers, where it feeds on mineral deposits in soap scum and fatty deposits in soap and shampoo residue.
Is Serratia Marcescens Dangerous? Since mold is dangerous to health, many think this pink film is dangerous. In most cases, unless you are in poor health, Serratia marcescens isn't harmful. It has been known to contaminate contact lenses, cause eye infections, and irritation.
Orange or reddish stains are caused by high iron in the water. You will likely notice these red hard water stains around your faucet or the waterline of your toilet.
Iron tends to add a rusty, reddish-brown (or sometimes yellow) color to water. If the color is more black than red, your water might contain a combination of iron and manganese. Both of these metals can cause staining of plumbing fixtures or laundry, but they are not known to cause health problems.
Lemon Juice and Water
Squeeze fresh lemons into a spray bottle then spray all the orange stains in your bathtub, being sure to fully coat the area. Allow the solution to sit for 10 minutes before scrubbing and rinsing. Repeat as necessary.
White Vinegar and Baking Soda
SLOWLY add drops of white vinegar to baking soda to prevent it from exploding in your face. Combine the two until you have a paste. Let this sit on the rust stains for up to 25 minutes (or until the rust looks like it's ready to come off). You might have to repeat the process.
Showers, with their constant exposure to water and humidity, are prime locations for pink mold. This mold can cause a range of health issues, from minor irritations to serious infections. To clean pink mold in showers, use a mold-killing cleaning solution and scrub the area thoroughly.
Tips to Prevent the Growth of Pink Mold
Keep surfaces dry. Since pink mold needs moisture to thrive and spread, take the time to dry the shower walls after each use. A squeegee can do the job in just seconds, or you can use a towel. Close and straighten shower curtains so they will dry more quickly.
It may not be as toxic as black mold, but pink mold has been linked to urinary tract infections, wound infections and gastrointestinal distress. It can also cause various ailments such as lung infection, rashes, allergy, and inflammation, bleeding in lungs, malaise feeling, and other respiratory troubles.
For most healthy people, Serratia marcescens or Aureobasidium pullulans shouldn't pose any health risks if you touch them while bathing or cleaning as long as they don't enter the body. (Avoid touching your eyes or an open wound with contaminated surfaces such as your hands.)
marcescens has been shown to cause a wide range of infectious diseases, including urinary, respiratory, and biliary tract infections, peritonitis, wound infections, and intravenous catheter-related infections, which can also lead to life-threatening bacteremia.
Pseudomonas aeruginosa was killed in 10 seconds by all concentrations of ethanol from 30% to 100% (v/v), and Serratia marcescens, E, coli and Salmonella typhosa were killed in 10 seconds by all concentrations of ethanol from 40% to 100%.
At least one day a week, spray surfaces with the vinegar or lemon juice solution before you see signs of staining. Let the solution work for a few minutes and wipe clean. Treat your toilet with vinegar at least once a month. These preventative measures will help you keep your home looking its best.
Use Vinegar & Baking Soda
White vinegar is a natural solution that can be utilized to dissolve calcium buildup. Sitting overnight, you will be able to remove lime buildup from the drain while avoiding the harsh chemicals in traditional drain cleaners.
It takes many years for the inside of pipes to develop clogs due to mineralization buildup. If you continue to let hard water run through your pipes, the blockages will eventually get worse.
Orange/Red Water Stains
Cleaning: If applied quickly, lemon juice or white vinegar work well to remove iron stains before they set in. For older or tougher iron/rust stains, we've found CLR to be a very effective, eco-friendly solution (part of the EPA's Safer Choice Program).
Fill a spray bottle with a 1:1 ratio of bleach and water, then spray any pink spots on your shower curtain and liner (if it's a colorful curtain, use a color-safe cleaner like OxiClean).