If you insist on using the old PWA interface instead of Google+, you'll see that the album limit is supposed to be 2000 photos. And indeed, it is. You can upload 2000 photos. But you'll only be able to see the first 1000. So it's really 1000 photos per album. But you can see all the photos if you use Google+, or even my Best Album app on iOS (not by Google).
Some discussion here:
I'm putting a link here because bookmarking them with your account is mind-bogglingly difficult, and this is even more so for Apple. It's as though they don't want you to keep track of their problems!