What is the black stuff growing in between my coping and tiles?
Black algaes are usually found growing on pool walls in areas of poor circulation, such as the deep corners of the pool. Is there such a thing as Mustard algae? Mustard algae, which most often grows on pool walls that are shaded, is easily brushed off surfaces yet is difficult to kill. Although mustard algae may not present problems in the same magnitude as green algae, this form of algae appears to be quite resistant to normal disinfectants and the addition of algaecide. Some swimming pool algae are also pink in color. Why do I have stains on my pool surface? When pool water becomes discolored or stains on the pool shell begin to appear, the actual color exhibited can often predict the pool problem being experienced. Colored water from any of the above algaes as well as minerals including iron, copper, and calcium can be the culprit. Minerals like iron, calcium and copper exist naturally in trace amounts in pool water. They may originate from the source water, that is, the watr used t
