Encrypt or hide Drobo 5C from local users


Hi everyone.

I’m working in recording studio on a Mac Pro. We are 3 users on 3 different bootdrives with 3 different OSX:

1: Me (High Sierra 10.13)
2: User2 (El Capitan 10.11)
3. User3 (Snow Leopard 10.6)

I’m the only Drobo user and I’ll be accessing the Drobo and storing personal files on the Drobo.

How do I hide the Drobo volumes from the other users on the Mac Pro?
Do I have to unplug the unit every time I use the Mac?
Can I create a Volume with a password?

Please let me know what I can do.

Best regards