Removing Mineral Deposits from Household Surfaces
(Note from NH: Though the methods below are useful,
there are situations where chemical changes to the materials have
occurred and NOTHING will restore the material to its original
condition. For example, streaky or milky-colored stains on shower
doors are often permanent because the glass has actually been etched by
the reaction of water-borne chemicals.
These can be prevented through the installation of water softening
equipment or (for the thrifty) simply wiping the doors dry after use.
Also, plated plumbing fixtures that have become discolored can be cleaned,
but often (especially on cheap brass plating or chrome) the coating has been
destroyed and no amount of cleaning can restore it.
In my personal experience with mineral accumulations around faucets and
on shower doors, I can unequivocally say that the
NUMBER ONE way to prevent mineral deposits is to wipe off standing water or
especially around the bases of faucets and on your glass shower doors (with
a towel of squeegee). Then you'll have a much easier time keeping
mineral deposits under control!!
Hard water is the cause of many problems... and makes
If you have hard water but don't have a water treatment system, you probably have more than your share of scum, film, and lime
deposits on a number of household surfaces. These unattractive deposits can appear on
china, porcelain, enamel, tile, stainless steel, fiberglass, chrome, and glass surfaces.
Hard water increases films and stains from soaps, minerals, and other substances.
Bathroom fixtures, sinks, dishes, and other surfaces need more frequent cleaning.
Calcium and magnesium in water leave hard deposits -- called lime scales -- on fixtures
and equipment. These minerals make cleaning products less effective. To clean away lime
scale, you need a cleaning product with "sequestrants." Sequestrants capture and
deactivate minerals in water. (Calgon is one example of a product with sequestrants.) The
deactivated minerals then cannot react with other materials to form scum, film, or lime
You may also have problems from manganese, iron, brass, or copper. Manganese leaves
brownish or blackish stains. Bacteria that thrive in water with a high iron content leave
a reddish or white slime. Brass and copper content in water are the result of acidic
water. When water is a bit acidic, it corrodes plumbing and fixtures. If you have brass or
copper fittings, you may end up with blue or green stains on fixtures. To remove any of
these metallic stains, use an acidic cleaner or an all-purpose cleaner.
The general types of cleaners discussed below will help you to remove stains on
household surfaces. It's best to clean stains away regularly. If they are allowed to
penetrate the surface, they become more difficult to remove. Be sure to follow label
instructions for safe use of cleaners. You may need to open a window or use a fan to get
Remember, some cleaners, such as ammonia and bleach, should never be mixed or used
together because they can form toxic fumes. Store cleaners in a safe place and properly
dispose of empty containers.
Acidic cleaners or straight acids are effective
Acids help remove hard water deposits. Some acid cleaners help remove discoloration
from aluminum, brass, bronze, and copper. Other acids remove iron rust stains. Acids are
typically found in toilet bowl cleaners, rust removers, metal cleaners, and kitchen and
bath cleaners that remove mineral products.
- White vinegar, a weak acid, is about 5 percent acetic acid. It may remove hard
water deposits from glass, rust stains from sinks, and tarnish from brass and copper.
- Lemon juice, another weak acid, contains citric acid, which can be used in much
the same way as vinegar.
- Oxalic acid is effective as a rust remover.
- Phosphoric acid is often found in cleaning products that remove hard water
- Hydrochloric and sulfuric acids are sometimes used in diluted concentrations in
toilet bowl cleaners.
Rust stains present a special problem on plumbing fixtures. Commercial rust removers
contain oxalic acid. If you purchase oxalic acid at full strength, dilute it with 10 parts
water. Follow all precautions when using oxalic acid, as this is a highly toxic product. A
commercial product like ZUD may be effective on rust stains because it contains oxalic
acid. When surfaces have become rough or pitted from repeated scrubbings with an abrasive
cleaner, ZUD or a similar product may be mixed with water to form a paste and left
standing on the stain for several minutes, then rinsed off.
For fixtures that are not acid resistant, clean with trisodium phosphate to remove the
rust. Cream of tartar, a mild acid, may be mixed with water to form a paste rust
Abrasive cleaners.. effective but use with caution
Abrasive cleaners like scouring powder may remove or lighten stains. Regular use of
harsh abrasives scratches the finish of sinks, bathtubs, or other fixtures. Once the
surface is dull and rough, it will get dirty faster and stain more deeply. Even mild or
fine abrasive cleaners may eventually scratch or dull surfaces. Do not use abrasive
cleaners on fiberglass, ceramic tile or glass.
Chlorine bleach can help remove some stains. Don't leave it standing for long periods
of time, as it will dull shiny porcelain enamel surfaces.
Some specialty cleaners are formulated to remove hard water deposits, soap scum, or
rust stains. Lime-A-Way is one example. Tub, tile, and sink cleaners that remove soup scum
and water hardness may contain sequestering agents and acids such as phosphoric,
hydrochloric, or hydroxyacetic acids.
Nonabrasive, all-purpose cleaners (like "409") in powdered, liquid, or spray
form are safe for most plumbing fixtures and can be used for regular cleaning and for
removal of hard water deposits and soap scum if the deposits are not heavy accumulations.
Stains at a Glance
Red, reddish brown (from rust or iron)
- Paste of borax and lemon juice; let dry, then rinse
- Paste of mild scouring powder, cream of tartar, peroxide; let stand 1/2 hour, then rinse
- Trisodium phosphate in water, then rinse
- Commercial products (like ZUD), then rinse
- Oxalic acid, 1 part to 10 parts water, then rinse
Green, blue-green stains (from copper or acid water)
- Soap suds and ammonia, then rinse
- Mixture of half water and half ammonia; rinse well and flush pipes with water after
Brown, black or others (from manganese and other minerals)
- Paste made of cream of tartar and hydrogen peroxide; let stand, then rinse
Hard-water marks, soap scum
- Paste made of white vinegar and baking soda; let stand, then rinse
- 1 teaspoon Calgon in gallon water, rinse well
- 2-4 tablespoons trisodium phosphate in gallon water, then rinse
The use of brand names in this document does not imply endorsement of the products
named or criticism of similar ones not mentioned.
Prepared by Dr. Sandra A. Zaslow,
Extension District Director, North Carolina Cooperative Extension
Service, North Carolina
State University, Raleigh, N.C.
This publication has been issued in print by the North Carolina Cooperative
Extension Service as publication FCS-397 and WQWM-12 (February 1993). Published by
North Carolina Cooperative Extension Service
North Carolina State University, Raleigh, N.C.
This article reprinted by THE NATURAL HANDYMAN with permission.