"I spent a lot of money on this product. I stained my sidewalks,patio,and pool area. I then coated it with their sealer with Shark grip added. That was a mistake. Two years later,it looks awful. Every bit of dirt adheres to it. There were a few places that I missed with sealer and you can see the big difference. My concrete looks like it's in a car repair shop. I spent over a $1000 and 2 weeks to make my outdoor areas look good. Now,I'm screwed. Tried every cleaner made,even muriatic acid,and it will not clean. Pressure washer won't even touch it. Had an H&C rep come out last year and finally gave up trying with them. This is one of those lessons you learn. My only option now,is to have it sandblasted. Can't afford that. It's a lot of square footage. If there are low spots where water pools on the concrete,it will remove the stain. Or,if water is dripping off a roof edge,it will remove the stain. I spent a lot of time prepping the surface also,so it's not that. It just kills me every time I walk outside and see how it looks. It gets worse every week. It's like a dirt and grime magnet. I'm so tired of our guests asking why we don't clean it. We used a white/gray tint that is now turning black."