The White And Brown Spots On Your Windows Are Stains From Hard Water. Hard water is water with high mineral content, such as calcium. When hard water evaporates, it leaves calcium or sodium (salt) remains behind, causing hard water spots to appear.
What they are is 'artillery fungus' sometimes called 'shotgun fungus' this is a fungus that is usually found on mulch (potted plants etc) it then under pressure fires an egg (the brown dots we see) onto anything it will stick to, that sometimes happens to be a window, it drys hard, and that's what we see on the window.
One of the first signs of water damage is often discoloration. As moisture seeps into the walls or window sills it often causes yellow, brown, or copper stains. It might fade with sun or rain, or the stain might be permanent and only get bigger over time.
As professional window cleaners we have found the only way to remove them from glass is by using a commercial grade scraper, after wetting the windows with a soapy solution. Most other methods simply scrape off the top of the spore, leaving a light brown speck on the window, particularly noticeable from inside.
After some research we discovered that it is called Artillery Fungus. Yes, aptly named because the fungus can shoot its spores at light-colored house-siding, fences, windows, and cars. These tough little fungi grow and develop in mulch made from wood during cool and damp conditions.
It forcefully ejects its mature spores high up in the air, leaving pesky stains. The good news is that while artillery fungus is a nuisance because it is unsightly, it is not harmful to humans or pets, it does not kill garden plants, nor does it cause any structural damage to the surfaces it lands on.
After the water dries up, what is left behind are white colored salt deposits of calcium and minerals. These stains leave a whitish mark on the glass surface, ruining its aesthetic beauty. If not removed immediately, these stains can form very thick deposits, which may lead to eventual deterioration of your surface.
Artillery fungus removal requires an abrasive tool. Power washing equipment is unable to lift the wood-decaying fungus, but PPW will help you remove similar contaminants that stick to siding, trims, roofs and the exterior surfaces of your home.
The presence of persistent, brown to black spots on cars, house siding, plants, and other surfaces may be an indication of the presence of the fungus Sphaerobolus stellatus.
Bleach, Simple Green, toothpaste and alcohol-based mouthwash have been known to work with various rates of success, and can be tried first before attacking the spores with a scraper. For removing spores off of cars oil, vinegar, car wax and tree sap remover have all worked for people that tested them.
Stains are brown spots on your siding that look like dirty water has dripped down your house. This is a sign of poor installation up by your rooftop. If not properly sealed, siding can allow rainwater in behind the siding, causing rot and staining issues.
Mounds of drywood termite fecal pellets are a tell-tell sign of a drywood termite infestation. Termite colonies eject pellets through a small “kick-out hole” in the external surface of wood from the internal termite galleries.
Over time, your aluminum window frames will lose some of their shine. Moreover, oxidation on the windows results in a dull gray-brown cast and white spots. Although the oxidation process prevents the aluminum from corroding further, it can be quite unsightly.
The discoloration manifests because there's a presence of mildew or mold, which is growing because the double-pane window offers the best place for mildew and mold to thrive, grow, and spread, feeding on whatever moisture is lingering, trapped between the panes, the humidity, and the darkness that allows it to live.
Mix a few drops of dish detergent with some warm water. Use this mixture to clean mold off the surface of the window frame or glass with clean cloth. If the area has a heavy amount of mold, use paper towels and dispose of the soiled paper towels in a plastic bag.
Brown mould will usually appear as dark spots and can even develop growths depending on how advanced it is. Brown mould can also start on the inside of walls and work its way to the outside so if you see start to it, it usually means there is a larger infestation.
Artillery Fungus and its Many Names
It is usually found in non-composted mulch because it doesn't go through a burning process that normally neutralizes fungus. Connected to the fruiting bodies are spore masses that are dark brown at their tips.
Artillery fungus may already be present at the site. It could be transported by wind from your neighbor's house. It may also be stuck to leaves that blow into your lawn. Another possibility is that it could come on nursery plants that you plant in your flower beds.
Power-wash the infected area with a strong chemical like outdoor bleach. Let the chemicals sit on the fungus for about 10-15 minutes. This has been known to kill the fungus, but not always. Again, Artillery fungus is tough, but bleach may keep it from spreading quickly.
While artillery fungus is mostly an outdoor problem, the spores can be found on walls and other surfaces indoors in certain cases: (1) if potted plants are top-dressed with hardwood mulch, or if (2) a potting soil is used that contains a large amount of wood product.
Even though there isn't any particular fungicide designated for the artillery fungus, one study suggests that mushroom compost holds some beneficial properties that would help suppress the diseases.
Professional window cleaners like Window Genie are trained and experienced in this battle. Window Genie uses a polishing paste specifically designed to fight the minerals that create these stains. The paste is applied to a non-abrasive cleaning pad and the window is lightly scrubbed.
One of the ways on how to clean glass windows from outside is to use a window squeegee. An extendable window squeegee allows you to clean high windows from ground level without the need to climb a ladder because they can be extended to several meters.
When you want to see clearly again, the best way to clean windows and other exterior glass around the house is with CLR® Calcium, Lime & Rust Remover.