Why You Shouldn’t Clean Your Windows with Tap Water

When it comes to cleaning windows, most people reach for a bucket, some soap,

and the nearest water source — usually the tap. While this seems like a logical and convenient solution, using tap water for window cleaning can actually do more harm than good. If you've ever cleaned your windows and noticed stubborn streaks or spots afterward, the culprit might be right there in your water.

The Hidden Problem with Tap Water

Tap water contains minerals such as calcium, magnesium, and sometimes iron. This combination is commonly referred to as "hard water." When hard water dries on glass surfaces, it leaves behind mineral deposits, which appear as white spots or cloudy streaks. These can be particularly visible in direct sunlight — exactly when you want your windows to shine.

The harder the water in your area, the worse the problem. In regions with especially hard water, mineral buildup over time can even etch or permanently damage glass surfaces.

What About Softened Tap Water?

Softened water might seem like a better option, but it still isn’t ideal. While many of the minerals have been removed, softened water often contains sodium or potassium, which can still leave residue behind. It’s better than hard water, but not a perfect solution.

Why It Matters

• Clarity: Hard water spots and streaks reduce the transparency and visual appeal of clean windows.

• Effort: You can spend extra time cleaning only to be left with less-than-sparkling results.

• Longevity: Over time, mineral deposits can etch the glass and frames, reducing the lifespan of your windows.

  
  

The Better Alternatives

1. Use Distilled Water

Distilled water is free from minerals and impurities. It leaves no residue behind and is perfect for streak-free, spot-free window cleaning. Pair it with a quality window cleaning solution or even a simple vinegar-water mix for excellent results.

2. Purified Water Systems

Professional window cleaners often use water-fed pole systems that rely on deionized and/or reverse osmosis water. These systems remove all minerals, ensuring a spotless clean without the need for harsh chemicals.

3. Rainwater (Filtered)

Filtered rainwater can be another good alternative. It's naturally soft, although it must be collected and filtered properly to ensure it's clean and safe for use.

Quick Tips for Streak-Free Window Cleaning

• Clean windows on a cloudy day or during cooler hours to avoid fast drying and streaks.

• Use microfiber cloths or squeegees for the best results.

• Always dry the edges of the windows where drips tend to gather.

  
  

Final Thought

Tap water may be the most accessible option, but it’s far from the best when it comes to window cleaning. For truly spotless results, ditch the tap and opt for distilled or purified water. Your windows — and your effort — deserve better.

Clear Bright Washing uses Purified Water Systems to clean windows to a clear bright view.