Good afternoon bwanab,
Thanks for coming to Apple Support Communities for help today.
We can't guarantee the photo organization you have come up with in the third-party app will carry over to iCloud and the Mac Photos app. To make sure the photos are archived, and to free up space in the iCloud System Photo Library for the new photos, we recommend the following:
- Make sure you have a Time Machine backup of your computer before making major changes.
Back up your Mac with Time Machine
- Export photos from iCloud Photos to an external drive. Confirm that you are able to open the images from the external drive before deleting them from iCloud Photos.
- Delete photos from iCloud Photos. You will need to go into the Recently Deleted folder and permanently delete them as well. Depending on the size of your iCloud Photos library and your internet speed, it could take a while for all of the files to process.
Here are some resources to help you with this:
Export photos, videos, slideshows, and memories in Photos on Mac - Photos User Guide
Archive or make copies of the information you store in iCloud
System Photo Library overview in Photos on Mac - Photos User Guide
Delete and recover photos and videos on iCloud.com.
"Delete photos and videos
- In Photos on iCloud.com, select the photos or videos you want to delete, or double-click a single photo or video.
- Click
, then click Delete. - Deleted photos and videos are moved to the Recently Deleted album.
- To permanently delete photos or videos before they’re automatically deleted, go to the Recently Deleted album, select the items you want to delete, then click Delete [number] Items.
Have a fantastic day!