Watermarks can appear whenever an item is partially cleaned. We've all done it. Something in the home got soiled and you decided to clean it, but you only cleaned the dirty part not the whole thing. Soon after you finished cleaning and everything dried out you noticed a ring around the cleaned area. That's a watermark. You can see in the photos above there is a watermark in the carpet. There is a clean area surrounded by a dark ring, a watermark. These photos were taken in a Tampa FL home where the AC unit leaked and flooded an area in the hallway.
The good news is that watermarks are easily prevented and can be cleaned up fairly easily.
How to remove watermarks:
It's really quite simple, use your favorite cleaning agent to spray the area with the watermarked area. While you let it sit and breakdown the discolored area get a spray bottle of water and spray the surrounding area. Make sure to get the area around the watermark as damp as the that your cleaning. This will make sure that the telltale ring won't develop. Now, clean the watermarked area with a towel to remove the soil. Let it all dry out evenly and the watermark will be gone.