ok so my wife decides to clean the tile at the top of the pool (inside the pool) area with a steel wool pad. tile looks great! but a few days later I noticed a lot of brown specs all around the edges of the pool where cleaning occurred mostly. so I figured (still do)it was rust from the wool pad. next I shut of the generator and let the fc down to under 1ppm. took 2 days. then treated it with aa. probably 2-4 lbs if I had to guess. I bought a 50 lbs box years ago. I have had brown staining before and the aa took if off within minutes. well this time it didn't touch the specs. I even put of glob of it right over top of some and nothing? I have some pics and will post my specs. any help much appreciated!! sorry if this was covered and I missed it.
fc 3.5 (before lowing to treat with aa)
20000 gal in ground fiber glass with swg