22Gb Library with no footage anywhere visible and nothing in the timeline?

Hello everyone! How are you? 
I'm new to video and FCPX. I've put together a few clips and rendered a few videos in a couple of years but nothing else.
Well, the thing is that I've created a new library and I've been doing some tests with some footage and also messing around with a recent acquisition (a 3D title plugin). I've deleted the footage from timeline and library after finishing my experiments and all the 3D titles were also removed from the timeline. So the library is apparently as when it was created. However, it still weighs 22Gb.

I am almost sure that this is normal and that those 22Gb are somewhere else because of the current setting that I have on FCPX. Am I right? And if so, is there a way of preventing FCPX of storing discarded stuff?

Any help is welcome
Thanks!

P.s: As this is my first post I want to say thanks to the creators of the forum, the people working on it, and the people posting, sharing and helping. 

Select Library. Control click > Show Package Contents. Here you'll find files that will never go away unless you delete them manually. In my case this shows the pig that optical flow creates. Note there are NO Original Media files in this particularly svelte library but the moment you create render or OF files then, buddy, watch out.



And, yes, you can purge them and the project will be fine. They'll regenerate the next time you render your edit.

Hello VTC. Thanks for your post. I'm sorry for my super late response. No excuse I though I'd receive an alert but I didn't. I have to get used to the forum.

I've done what you've said and there's nothing there. Please, bare with me. I'm super new in this world. I've just realised that all those GB are in Cache. Is this normal or is it because of my settings on FCPX?

Thanks so much. I'm going to check my profile and see whether I can get notified when I get and answer.

Best!

In FCP select the library and use File>Delete Generated Library Files. Checked everything in the dialog. See if that does anything.

It did, Tom. Thanks so much I'm little by little getting to know the software.
Thanks!