Reddish Stains On Sinks, Toilets and Fixtures
Reddish or red-brown stains are usually associated with iron in the water. The water should be tested to measure the amount and type of iron.
Iron types found in water are:
Each of these types presents a potential problem!
As little as 0.3 ppm in a water supply can cause staining of clothes and fixtures.
Oxidized iron is insoluble in non-acid water. When water containing soluble iron is exposed to air, the soluble iron reacts with the air to form oxidized iron which precipitates if there is sufficient alkalinity present. Usually about 100 ppm (parts per million), of excess alkalinity is necessary for complete precipitation. If surface waters contain iron, the iron is usually oxidized. Well water supplies frequently contain a mixture of the air to form oxidized iron which precipitates if there is
sufficient alkalinity present. Usually ab
Water containing oxidized iron is filled with reddish rust particles visible in the water when first drawn from the tap. This is commonly referred to as red water iron. Red water iron causes the same problems which are caused by clear water iron. Reddish-brown stains on clothes, porcelain, and cooking utensils. When iron water is mixed with tea, coffee or alcoholic beverages, the mixture commonly referred to as red water iron. Red water iron causes the same problems which are caused by clear water iron. Reddish-brown stains on clothes, porcelain, and cooking utensils. When iron water is mixed with tea, coffee or alcoholic beverages, the mixture turns black. Red water iron causes less of a metallic taste than clear water iron, but the taste is still objectionable. Filtration is the easiest method to use for removal of oxide.
Soluble iron is often called "clear water" iron. Clear water iron is easily recognized because the water is clear when first drawn from the tap. However, after coming in contact with the air, the iron oxidizes, or "rusts", forming red or reddish-brown particles in the water. It is commonly found in well water supplies throughout the United States.
The main objection to iron water is that it causes reddish-brown stains on plumbing fixtures, porcelain, cooking utensils, and laundry. Iron causes a disagreeable metallic taste and can have a sewer type odor. Iron causes coffee, tea, liquor, and other beverages to turn inky black. As little as 0.3 ppm (parts per million), is enough iron to cause staining.
Soluble iron problems can often be treated with a water conditioner, or a system containing a softener and filter. An iron filter that recharges with chlorine or potassium permanganate can also be used. Feeding chemicals to oxidize the iron followed by filtration with a mechanical filter is another means of treatment.
Very small particles of oxidized iron suspended in the water is called Colloidal iron. In this case the particles are extremely small, (less than 0.1 micron). Typically, they are combinations of iron and other substances, bound tightly together. Like colloids they do not settle out and can't be removed by ordinary filtration. Frequently, colloidal iron is mistaken in appearance for color rather than turbidity. Colloidal iron looks more like a colored water because the particles are so small that they cannot be seen.
When water comes in contact with iron-bearing rock in the presence of decaying vegetation, conditions for forming this kind of iron exist. Colloidal iron may be present in shallow wells or surface water supplies. It is seldom found in deep well supplies.
Like other forms of iron, colloidal iron causes reddish-brown stains on laundry, plumbing fixtures, and cooking utensils. When iron water is used in tea, coffee or whisky, the beverage turns unappetizingly black. Iron water has an unpleasant metallic taste.
Whenever iron is oxidized from the soluble state to the precipitated state, the particles first formed are molecular in size. These particles agglomerate to form larger clumps, which may become large enough to settle, or they may stop growing when they reach colloidal size. In the presence of decaying vegetation, the tiny particles may combine with the organic matter. When this happens, the organic matter causes the particles to have a static electrical charge and they repel each other. Since the particles repel each other, they cannot floc together to form larger particles. In the absence of organic matter, the particles will floc together and grow in size. Soon the particle floc becomes large enough to settle out of suspension. At this point the oxidized iron is no longer colloidal and can be removed by ordinary filtration.
There are two types of treatment typically aimed at Colloidal iron problems. The first is to feed chlorine into the water. Chlorine will oxidize the substance to which the iron is bound and so allow the iron to be removed. The second method call for the feeding of polymers that are attracted by the static charge on the particles. When this occurs, larger, filterable clumps are formed. These larger bodies can then be removed by mechanical filtration.
Iron bacteria are living organisms that feed on iron in the water and on iron in wells, piping, tanks, and iron futures. They build slime in toilet water closets and clog pipes, pumps, water heaters and
appliances. Bad tastes and odors in the water supply are often common with the presence of iron bacteria. Often, some of this slime material breaks free in slugs at high flow rates, causing extremely discolored water. Larger clumps can cause plugging of fixtures. Bacterial iron can
be identified by a reddish slime-like material in the toilet flush tank.
Until the last few years, iron bacteria were not too common a problem but their presence has increased very rapidly throughout the country and is now quite prevalent. You may expect that an iron water may at some future time be invaded by iron bacteria.
Iron bacteria must be killed by chlorinating; filtration alone doesn't eliminate them. Bacterial iron is difficult to treat. The bacteria must be killed. The usual method is through chlorinating. High levels of chlorine are introduced into the plumbing and allowed to flow throughout the home to kill all all the bacteria. Superchlorination of the plumbing, toilets, pressure tank, and water heater may relieve the problem. Depending on the severity of the problem, often chlorine must be fed continuously to prevent future growth.
Iron has the ability to combine with tannins and other organic materials
in the water. The materials that result are almost impossible to remove
through ion exchange methods or oxidizing filters. If tannins are
present, they are probably combined with the iron. Some levels of
organic iron can be removed by a carbon filter. However, the carbon
material must be replaced after it becomes saturated. Higher con
impossible to remove through ion exchange methods or oxidizing filters.
If tannins are present, they are probably combined with the iron. Some
levels of organic iron.
Blue or Blue-green Stains on Fixtures
A Case Study from New Mexico, featured in Water Conditioning & Purification Magazine, March 2001.
If there are blue or blue-green stains on sinks, baths and porcelain, there is probably copper in the water supply. Copper is a metal which is seldom naturally present in a water supply. Copper is found in water supplies around strip mines, but usually when copper is present it has been introduced by the corrosion of copper plumbing. Water containing copper cause blue or green stains on fixtures. Copper is toxic to aquarium fish and can impart an undesirable taste to the drinking water. Copper is a problem in the processing for color photography because it changes the color value in prints and transparencies. Beauty shop operators have a problem when copper is present because it causes color variation in hair toners, especially for blonde. Copper also causes green soap curd to form. It is corrosive to aluminum. Test for copper by looking for the blue or green sans on porcelain fixtures. This is a sure sign of copper in the water. The amount of copper can be found by sending a water sample to a lab for testing. Copper is not usually considered harmful to humans but concentrations in a range of 1 – 5 parts per million cause an objectionable taste.
A water softener removes copper. The capacity of a water softener for copper removal is about the same as for iron removal. The best way to treat a copper problem is to eliminate the corrosion problem. Make sure that dielectric unions are used for all plumbing connections between copper and galvanized pipe. Also raise the pH of the water to at least 8.3. If the water already has a high pH, feed polyphosphate and/or silicate chemicals into the water to protect the plumbing from the
effects of corrosion.