elmarfromdallas

Same as you delete any photo - select the photo and delete it (on the Mac Command delete is best)

Or maybe as a wild guess the real, un-ask question is how to identify duplicate photos - That is not a feature of Photos although it does detect duplicates during import and when syncing to iCloud Photo Library - if you have created duplicates due to user action then there are three safe, tested programs to identify them so you can delete them using Photos -- PowerPhotos -- Duplicate Annihilator for Photos -- PhotoSweeper for Photos (best and finding similar but not duplicate photos) - other programs might damage your library and should not be used - Using third-party apps to remove duplicate photos might damage your Photos for macOS library - Apple Support

LN

You don't want an app to automatically delete the photos. If there's an error they are gone. You want an app to identify the potential duplicates, put them in an album or mark them with a keyword for easy retrieval and deletion by yourself.

These applications will identify and help remove duplicate photos from a Photos Library:

• Duplicate Annihilator for Photos - $7.95
• PhotoSweeper - $9.99 - Demo version available.
• PowerPhotos - $29.95
• Photos Duplicate Cleaner - Free

PowerPhotos is the iPhoto Library Manager version for Photos and is very powerful. Although more expensive I would recommend it as it has more capabilities than the others like the capability to merge Photos libraries or copy photos along with their metadata between libraries.

PhotoSweeper compares bitmaps and/or histograms so it can detect duplicate images even if they have different sizes, file names, sizes and capture dates.

If you use the recommended programs you do not do it one by one - they create an album of the duplicates and you review it and delete any or all from there (command - delete) - it would be insane to have a program automatically delete photos without your review - that would guarantee loss of critical photos

there are three safe, tested programs to identify them so you can delete them using Photos -- PowerPhotos -- Duplicate Annihilator for Photos -- PhotoSweeper for Photos (best and finding similar but not duplicate photos

LN

adn that has not hppened

The computer has doubled or tripled that amount on its own.

In no case will Photos ever double or triple storage for Photos - we still have no idea what exactly you are seeing or what you have done but we do know that the computer NEVER duplicate photos - it only does what you tell it to and NEVER does anything on its own - I have over 130,000 photos in two libraries dating back to the early days of iPhoto and migrated forward over and over and not a single time has "the computer" ever added a duplicate

if you provide facts and not hyperbole we can help - you have gotten multiple posts explaining how Photos works and you have not yet given anything concrete to work with except incorrect claims

Duplicates are hard to create and easy to fix in spite of your incorrect climes to the contrary

LN