White water stains are generally made from something wet sitting on the wood, and may not be very deep. Black water stains usually reveal rot from below or on the underside of the wood, and usually goes all the way through the wood. Try a suggestion or two, but be prepared to remove boards or pieces of boards and replace them, including sanding, staining, and sealing them to match the others. ☺️
After removing old carpet and padding from the floor of a fixer upper house we bought, we want to remove stains without sanding right now if possible .
https://www.hunker.com/13415255/how-to-remove-dark-water-stains-from-hardwood-floors
You will probably have to buff it all out or sand it down and then we finish it
Refinish*
Here is an article that might help - https://www.todayshomeowner.com/video/tips-on-removing-stains-from-wood-floors/
Here are some things to try:
https://www.todayshomeowner.com/video/tips-on-removing-stains-from-wood-floors/
https://www.hunker.com/13415255/how-to-remove-dark-water-stains-from-hardwood-floors
https://www.accutechrestoration.com/how-to-remove-black-stains-on-hardwood-floor/
White water stains are generally made from something wet sitting on the wood, and may not be very deep. Black water stains usually reveal rot from below or on the underside of the wood, and usually goes all the way through the wood. Try a suggestion or two, but be prepared to remove boards or pieces of boards and replace them, including sanding, staining, and sealing them to match the others. ☺️