If there happen to be small limescale deposits, you can try to remove them using some vinegar, better if lukewarm, or water with lemon juice. Once applied onto the glass pane, leave it on to act for some time, then remove with a soft cloth applying a certain pressure, then rinse. It might be necessary to repeat this operation several times. The use of excessively aggressive products is not recommended, because they may damage the finish of aluminum profiles.