Designate "Use as System Photo Library"

Oh yes, yes I know. But once you select a library as the system photos, I have used power photos to merge library‘s and now would like to unselect it. Then open my newly formed combined library as the new system library, but there’s no way to unselect once selected. I’m thinking Juan just need to quit photos, open photos with the option key and select the library of choice. Then one will be able to select that library as a system for library, yes? Thank you for your kind response, best Seth

Say, thank you. I was thinking it must be something along these lines. So, just db click on any other photo library and in preferences for photos will have the "Use as System Photo Library" reset? Best, Seth

Thank you for everyone’s responses and assistance here!

I believe I am merging seven different Photo libraries, finally, after purchasing PowerPhotos, which I’ve been contemplating for a couple years now. I thought the end product would be 200+ GB, but there were so many duplicates it looks like it’s going to be more like 80 to 90 GB, which will fit my iCloud package 📦. I remember every photo got duplicated, and showing up in iPhoto’s and perhaps Photos as well for quite a while, and I think it was photo stream and iCloud photos each Inserting The same photo and ended up showing duplicates of most photos. I thought that had all been corrected, but apparently the photos got scattered instead of being placed side-by-side, in iPhoto or photos apps, however, maybe someone here knows what was going on during that period of time and when it was fixed, as it’s not happening with new photos for some time.

Again, thanks to all.

Best, Seth