Removing Dark Spots From Hardwood Floors. Apply hydrogen peroxide on your hardwood floor stain in sections. Simply moisten the rag or soft absorbent cloth like felt and apply to the spot.
Repeat for longer hours if the stain. Wipe the floor with a damp cloth If the stain. Apply the paste to the entire area of the stain and then use a cloth or a toothbrush to rub the paste around on top of the stain as in Figure 4.
Then wipe up the hydrogen peroxide area with a clean dry cloth and allow to dry.
On the other hand it poses a bigger problem and will be harder to remove. Apply a small amount of toothpaste to the stain and buff gently with a soft cotton cloth. To remove dark water stains from wood floors you have two options. Alternatively you can strip sand and reseal the area if possible.
