Removing excess filler or stain over

Hi all- I recently repaired and sanded my 100+ year old floors in my home. I went over everything with a drum sander and edger. Before the final grit, I trowel filled the entire floor and then did one more pass with the drum and edger before returning them to the store.
Unfortunately, due partially to some dents and excess filler, there is still a good amount of filler left in areas on the floor.
I'm wondering, should I just go ahead and stain the floor or do I need to remove all of the filler?
My preference is to remove the filler to get as much bare wood as possible.
Is there an easy way to do this or will it require just good old elbow grease?
I have tried re-wetting the water based filler in a few areas and it seems to come off fairly easily after wards but I don't want to get the boards wet of this is a bad practice. I had some success also with fine grit paper on a belt sander but it's still a time consuming operation.

I'm fine with the indentations as it looks much better than it did before and I'm not expecting perfection.

Thanks for any advice.

 

Here are some photos. Hopefully these come through. Taken off my iPad.

 

Get an orbital floor sander from the rental store and keep sanding.

 

I agree, more sanding is needed. Use an orbital sander - you can get in trouble quickly with a belt sander! What color stain do you intend to use? For future reference it is often better to live with many of the defects in an old floor than try to get it all smooth like a new one. Fillers look best when they fill minor cracks or defects.

 

Thank you both. I'm about to go to the store and get an orbital sander. I should have only spot filled. I'm planning to use a dark stain. Walnut

 

Once you get the orbital, you probably need to go back to course grit... fine sandpaper is not going to remove that filler.

 

The filler should have been applied after the first sanding cut, this should give you an idea of how much sanding was needed if applied at the correct time.

 

Yeah... I wish I had said that. Lol. I'm worried about those long vertical lines of filler... hope they aren't places the drum sander grooved the floor.

 

IMO the vertical lines of filler in the wood [not at the cracks] won't be a big issue, I think the gobs of filler are going to be the biggest concern.

 

I think you did say that lol.

It looks like agreed, this floor should be completely re-sanded. The drum sander can wreak havoc.

 

I've never seen anyone skim coat a floor before, I guess there is a first for everything.

Also for future reference, wood filler is for nail holes and minor imperfections. It is not intended to replicate the wood and will not stain up to look like the wood either. Depending on your success sanding, the fail safe fall back is to float and new engineered floor over the top of this floor.