Is there any way to remove dark spots or 'burn marks' after 30-inch chlorine tablets are left on the bottom of a gunite plaster pool?
The black (burn) marks show up on Gray plaster pools. White plaster pools will show up as a yellow or rust color. Remove the tabs and put them in a proper floating devise, the marks will go away in time.
Try using wet and dry sand paper on the burn marks to reduce their visibility and roughened plaster.. additionally, tablets of any size should NEVER be placed or tossed into the pool or skimmer. K