Toilets often develop a pink or slightly orange ring around the bowl right at the waterline, especially if the toilet is rarely used. It probably isn’t rust or a mineral. The bad news is that slimy, anaerobic bacteria called Serratia Marcescens to cause this ring. The good news is that this bacterium is generally harmless in your home, although it does cause problems in hospitals and other places where people are immune-deprived. In those situations, it can cause urinary tract and wound infections.
The bacteria are called anaerobic because it does not use oxygen to sustain life. Serratia Marcescens also causes stains in the tub, behind or around the sink faucet, at the bottom of shower curtains, or wherever surfaces are moist or water pools for a period of time. It also feeds off of fatty substances such as the residue of soap or shampoo. This bacteria is present in the air and has nothing to do with the quality or type of water coming out of your tap. The red, pink or orange color is caused by a pigment produced as the bacteria colonize. In the middle ages, it inspired reports of “miracles” in damp climates where it grew on bread and locals were convinced the red pigment was the blood of Christ. Today, its growth in bathrooms is unsightly and most homeowners strive to eliminate it.
In their haste to remove the bacteria, some homeowners make the mistake of scrubbing the porcelain with something harder than porcelain, such as a metal brush. This scratches the porcelain and creates more surface area for the bacteria to breed at the surface of the water, and should be avoided. Chlorine does kill these bacteria effectively. Most municipal water is slightly chlorinated, but chlorine tends to dissipate when water pools and sits as in a toilet bowl. In-between cleanings chlorine may not be present at all. Resist the temptation to pour chlorine bleach into the tank or toss in a chlorine bleach sanitizing brick. Chlorine damages rubber parts in the tank such as the flapper, causing the flapper to deteriorate more quickly. This can quickly lead to a leak into the toilet and an unwanted increase in your water bill! The best way to deal with the pinkish ring is to tackle it in the toilet bowl with chlorine bleach and a plastic-bristled brush. For hard-to-reach areas, try an old toothbrush dipped in chlorine bleach, being careful of course to wear gloves and protect your eyes from the harsh chemical. Be sure to clean frequently to keep these ubiquitous bacteria at bay!