Different Key Signatures in Bass & Treble (Piano)

I’ve written a piece for piano that has the left hand playing in C Major and the right hand in E Major. I would like to have the key signatures reflect this but whenever I change one staff the other one automatically changes to match. How to I edit each key signature separately?

(Also, how do I delete a Tonalitly System that I created by mistake?)

When you enter the right hand key signature (shift K to invoke the key signature popover, then type E), alt-return will put your key signature in that staff only. This also works for time signatures (shift M), which is really cool.

For tonality systems, you should be able to click on its signpost (make sure signposts are turned on in the View menu), and delete it.

You can delete key signatures that reference a tonality system (as Stephen Taylor said) but I don’t think you can delete the tonality system itself.

If you never use it, it’s not going to cause any problems. If you really want to be tidy-minded, open a new project and copy all the music into it.

That’s perfect, thanks for your help.