I am refinishing the red oak hardwoods in my house.

I just finished sanding my wood floors, went great.

Had some dog urine spots that I cleaned up with peroxide. They lightened nicely over a few days of treatments.

Just stained it and spots of a different color are showing where the peroxide was. Anywhere the peroxide was is darker.

Stain color is Jacobian.

Help Please, what do I do now?

Thanks for sharing your expertise.

You can start with using fine sandpaper or coarse steel wool, number 2 or 3, to try to remove some of the stain from the surface by rubbing very firmly. The bleach can soften the wood fibers, which means they will absorb more of the stain. Scraping off some of the color will help, but it will not have the same beautiful grain definition that untreated wood has. You will be working as an artist to complete the job to your satisfaction. Adding some lamp black to the seal coat will help the adjacent areas come closer to the same color, without using any tint in the already darker areas. I would seal the darker areas after you have removed some of the stain and let it dry before you add tint ant coat the remaining flooring. Practice with some scraps or use a white sheet of paper to determine how much color to add so you can blend the darker areas to area that didn't get urine stained. It may take more than one coat of tinted finish to get real close. As your final coat, to get the right gloss level, use no color, since this will be protecting the tinted coats from wearing off.

Thanks for the input. Most of what you said is over my head.

I will try the first part of removing some of the over staining per your advise.

It is not practical for me to try to spot treat as I poured the peroxide willy nilly and over used it.

May just

1)resand and start over
or
2)maybe try to peroxide the whole floor over the current stain and restain after

Think there is any merit with these ideas?

If you go with the second option (peroxide everywhere) you'll void any warranty you had for sure, and have a difficult time keeping things even on the next coat of stain. Sand and refinish is probably the best bet, as long as the peroxide stains don't run too deep into the wood.

Another route may be to cover the area with a rug if possible. Simple solutions are sometimes the best!

Did you resand the spot where you put peroxide before staining?if you didnt the peroxide probably popped the grain which is why its darker. the more the grain is open the darker it is.

I used the peroxide after sanding, no warranty, floors are 40 years old.

If you do decide to sand again you will expose the stain as darker than the surrounding wood, again. Most floor mechanics don't have time to play around with bleaching the dark areas which creates different problems. One way to make the stained area less noticeable would be to polish the surface smoother than the surrounding area. If you finish your whole floor with 100 grit, then use 150 to sand the dark area it will absorb less stain. Hand sanding around the stained area with a coarser paper by hand, say 60 grit, will help blend an area around the stain, too. A dark stain will be the best to start with. The urine stain will have no red hues, so it would help to have a tint this color to add to the urine stained area to have it stand out less. You will also be able to make the whole floor surrounding the stain absorb more stain by wetting the surface with water to pop the grain, opening the grain to more stain being soaked into the surface, kind of like wetting with bleach, but with clear water. These are two ways to prepare the wood for a more even stain color.
Another technique to diminish the contrast is to use a lighter stain color, or thin the stain with a natural colored oil to dilute the color, if you are using an oil based stain.
Since it takes a high level of talent to make stains acceptable the best solution to pet stains is to replace the damaged wood with new wood matching the specie and grain pattern by finding patch wood that is as close to the original flooring as possible. Of course new wood may have it's own challenge in blending with the existing old flooring.

Thanks for all the great input, I will give these ideas a try and repost after.

Thank you all.