1___2___3___4___5___6___7___8___9___10___11___12___13___14 Acids: Neutral: Alkalis: Acid Bowl Cleaners Marbalex Strippers Vinegar Marbamist Degreasers Most Fruit Juices Marbadan Ammonia Alcoholic beverages Stone Quest Most all purpose Many household and household cleaners. bathroom cleaners. Dirt and soil Many natural stones Most stones used today are sensitive to both acidic and alkali cleaners One reason is due to the fact that most stones are classified as hydroxides which classifies them as natural alkalis. Alkalis usually do not damage stone as quickly, however, they will cause deterioration. The corrosiveness of acids cannot always be measured with the pH scale. In most instances, the lower the pH number the stronger the acid. A solution with a pH level of 1 is usually stronger than a solution with a pH of 4. However, there are some acids with a higher pH that are stronger than an acid with a lower pH. On the alkali side, the higher the pH number the stronger the alkali should be. A solution with a pH balance of 12 is usually stronger than a solution with a pH of 9. When using an alkali cleaner, never use hot water because it may create a stronger alkali reaction with adverse affects. Understanding pH balances will help select the proper chemicals that can be used on stone. However, a main factor to remember when selecting a stone maintenance chemical is the activity level. For example, most neutral cleaners have a pH balance of 7; however, some neutral cleaners are stronger than others because they have higher activity levels. There are many neutral cleaners that are not active enough to thoroughly clean a stone's porous surface. There are also an abundance of neutral cleaners that are too active for stone to endure. Many neutral cleaners have high activity levels that are corrosive to many stone surfaces. The neutral products have suitable activity levels that are safe on all stone surfaces, if used properly.