well, we left on vacation for a week and left the neighbor in charge of basic maintenance. apparently "put 2 pucks in the floater" was interpreted as "toss 2 pucks into the pool" as we now have a pair of softball sized stains on the bottom of the pool when we got home.. from some quick searches it appears our only hope is to treat them as metal stains? I'll have to snap some pics but it appears the pucks bleached out the plaster (light blue) as opposed to leaving a dark stain (metal?). any other suggestions?