Cleaning concrete pavers?
I recently put in a walkway of concrete pavers. We had a pretty wet summer, and part of the walkway was submerged by an inch of water. Now the pavers have some sort of black spotty stains all over them. First I tried a green product, but it did nothing. Then I tried a bleach solution. Nothing. Then I tried a stronger bleach solution with laundry detergent mixed in and let it sit a while. Nothing. Then I pulled out the muriatic acid, mixed up a strong solution and poured it on. The paver smoked, but the stains remain. Is there anything that can get these ugly stains out?