Do NOT leave the chlorine pucks on the spots long; they will etch &/or discolor the surface.

You'll need the K2006 kit in order to manage the chlorine levels you'll need to get rid of the stuff. Getting a good nylon bristle pool brush would help, too. (If you use it!)

Did you really put 20# of stabilizer in? That's about 60ppm, if it all dissolves! If you did, turn your feeder UP, and use an cheap OTO drops chlorine test to check chlorine levels. You'll need to stay in the dark yellow range.