Photos DID duplicate my library. How can I fix that?

Photos was automatically installed on my machine when it was released. After it finished it automatically started to import my iPhotos library. I now have an iPhoto and a Photo library as expected. However, each library takes up the same amount of space (around 295 GB). When I look at the folder size of my Pictures folder it is around 600 GB. My question is are they actually duplicated and if so, how do I fix that?