Whether the chlorine stains on your window are caused by splashing pool water or an old cleaning attempt, you can typically remove the stains by thoroughly cleaning the windows again. Although chlorine often causes a bleaching effect on carpet and fabrics, chlorine typically only leaves a type of whitish water spot on glass. You'll need the right tools to scrub these sometimes tough-to-remove spots away.
Mix 1/2 tsp. of liquid hand soap or dishwashing liquid, 1/4 cup white vinegar and a 1 3/4 cup water in a spray bottle to create your window cleaning solution.
Spray the solution on your cleaning sponge or window scrubbing wand. Scrub the window with the solution, starting at the top. Spray additional solution onto the sponge, as needed, to keep the window moist.
Scrub the window a second time, paying close attention to any stains. This will help remove excess soil and tough stains like your chlorine stains.
Use your sponge or wand to wipe along the edge of your window to remove any built-up dirt along the edges.
Wet the edge of your squeegee blade with water. Wipe the edge with a damp cloth to remove the excess water. Place the blade in the top corner. Slide the squeegee down across the window in a reversed-"S" or "S"-pattern to remove the soapy solution from the window. Wipe the tip of your squeegee with a damp cloth. Repeat the process until you've cleaned the entire window.
Run the squeegee blade along all the edges of the window to remove any excess soap which may have built up there.
Use a damp cloth to wipe away any dirt or water left on the edge of the window frame or the window sill.