Water Stains? How to Identify The Top 5 Stains
Does your well water cause pink, red, brown, black, or blue stains to appear on your fixtures or appliances?
Unsightly stains can show up on fixtures and appliances or when washing laundry as well as your hair. These stains show up generally as pink, rust or reddish, black colored, dark brown, and green stains.
Pink stains: Pink stains on the toilet are not uncommon in well water or city water that is low in chlorine. However, this is not caused by the water itself; rather, it is caused by airborne bacteria. To eliminate this problem, keep the toilet cleaned often with a small amount of bleach.
Red or rust stains: Iron is one of the most common elements in the Earth's crust and is found in ground waters worldwide. The maximal contaminant level (MCL) established by USEPA guidelines is 0.3 parts per million, also known as 0.3 milligrams per liter of water. At concentrations higher than 0.3 ppm, iron in well water can stain fixtures and clothes and give the water a bitter or rusty taste.
Iron is usually found in a dissolved (clear with no color) state in well water, and the water may appear crystal clear whenever first used. After exposure to oxygen, or after the addition of oxidants (such as chlorine bleach or hydrogen peroxide), this ferrous iron will be oxidized (“rusted”) to the ferric form to form insoluble particles. The well water then looks reddish, orange colored, or even yellow, or in the situation with manganese, black or brown. This may happen in toilet flush tanks and inside your clothes washer or even dishwasher. An iron analysis will tell you if this is the cause of the stain and just how much iron is in the well water.
Light brown or tea-colored stains: These are usually caused by manganese. Manganese is also a common component in the Earth's crust and is also found in many ground waters. Manganese is not generally regarded as toxic. However, some research has shown it causes stomach upset and diarrhea when it comes to levels over 0.05 ppm. The maximum contaminant level (MCL) set by EPA standards is 0.05 parts per million, at times labelled as 0.05 mg per litre (mg/L) or 50 micrograms per liter (ug/L).
In concentrations higher than 0.05 parts per million, manganese in water can cause discoloration of sinks as well as clothing and give a sour, asphaltic, or greasy flavor to water. Manganese is frequently found in a dissolved form in water, and the water may appear clear when first used. After exposure to air, or following the addition of oxidants (including chlorine bleach or ozone), the clear manganese will be oxidized (“rusted”) to produce solid particles of manganese oxide. The well water then can look dark brown or black while having an oily surface or appearance. This can happen in toilet flush tanks and in the washing machine or dishwasher.
Tannins found in water by organic material from decaying plant life can also leave tea-colored staining and light brownish streaks in your washing. Have the water tested for tannins as well as iron and manganese..
Black staining: This can be brought on by iron sulfides that are formed through the combining of iron and sulfates in water. This is most typical in water that has a strong sulfur smell. This can also be caused by manganese and/or manganese sulfides. Analyze for iron, manganese, sulfates, and hydrogen sulfide to determine the cause of dark-colored staining. A high concentration of manganese also causes black deposits and staining.
Blue staining: It begins with blue staining on your fixtures and tubs. You may notice laundry washing spotted with light blue, and the drinking water may have a bitter taste. Eventually, the copper pipe corrodes, and then you begin to see pinhole leaks. These problems are caused by your copper pipes corroding.
Copper water pipe deterioration is often caused by water that is lower on the pH scale, which means acidic well water. It may also be brought on by water that is high in pH and total dissolved solids. These complications can be easily fixed only if you can correctly determine what the water chemistry is first. To identify this problem, analyze for pH, alkalinity, hardness, total dissolved solids, and copper. Once you have these numbers, a Langelier Saturation Index, or LSI calculation, can be carried out, and it will help identify if the water is corrosive.
Frequently Asked Questions
1. What causes pink stains in my toilet or shower?
Pink stains are usually caused by airborne bacteria like Serratia marcescens, not the water itself. These bacteria thrive in moist environments with low chlorine levels. Regular cleaning with diluted bleach can help eliminate them.
2. How can I tell if the stains are from iron or manganese?
Iron usually causes red, rust-colored, or orange stains, while manganese causes dark brown or black stains. A water test can confirm the presence and concentration of these minerals.
3. Why does my well water leave black stains?
Black stains are often due to manganese or iron sulfide. If your water also smells like rotten eggs, hydrogen sulfide gas may be present. Testing for manganese, iron, and sulfates can help identify the issue.
4. What does blue staining indicate?
Blue or bluish-green stains typically come from copper pipe corrosion, often caused by acidic or highly mineralized water. Over time, this can lead to pinhole leaks. A pH and copper test can help diagnose the issue.
5. How do I prevent future staining from my well water?
The first step is accurate water testing to identify what's causing the stains—iron, manganese, tannins, or pH imbalance. Based on the results, targeted treatment solutions like oxidizing filters, neutralizers, or softeners can be installed to prevent staining.
