I have tried every remover product on the market following the label directions. NOTHING BUT NOTHING is aiding in the removal. Last year I used the cl free system. Had several large stains and green stains. Had pool emptied and acid washed. Changed to a salt generator and now the staining is all over... walls and floor of pool. light markings all over. Tried test kit from pool store and nothing helps. I am open to all ideas. i will attach a few pics. i will be grateful for any help you can offer.