I have a pretty bad black algae problem, and I just don't have the strength/ability to budge most of the spots by hand with my wire brushes. Kind of a double whammy now that chlorine is so very expensive/harder to find, especially as I am on a pretty tight budget. I just cannot afford to do a SLAM even if I had enough chlorine to do that right now, and here in Texas we are already going to be up to 100 next week! I am worried about the coming summer. I can't believe as hard as this scrubbing is to do, that someone hasn't invented an automatic scrubber similar to a vac that can be put in the water and help me scrub these areas! Has anyone heard of one??