Thank you for your response.
I have imported the photos in iOS by dragging folders to the Photo app.
I have not imported anything from Ipad, Iphone of Ipod touch.
I have now run PhotoSweeper X and removed a lot of duplicates ( as Apple has not provided a utility tool to detect duplicates in the Photo app) . Even so more than 10000 photos appear as unallocated to albums, having checked a few they DO appear in Albums so I am really confused now as how can they be and not be in an Album...I have deleted recently a lot of photos and also deleted them from Recently Deleted folder yet the Smart Album still pick them up as does my other macs and Ipad. How long does it take to be removed from Photos ?..days ?..weeks ?..
This could possibly be the explanation for unallocated items...they are parasit files, files that don't appear anywhere unless a smart album looks for them..
I am going to have to ask you how can I delete ALL photos from the Photo app ( some 36000) and be sure that NONE exist saved somewhere in the cloud. How long will it take to ensure there's NONE in the app before a start rebuilding my photo library in Photos , hopefully this time without duplicates and no unallocated files ??
Please answer above and of course I would welcome any other suggestions...am at the moment not very happy with Photos, other cloud providers seem much more attractive.