G-RAID 4TB Encryption El Captian

Is there a way to encrypt the G-RAID drives in El Capitan that doesn’t involve a 1 minute per gig encryption? I tried using disk utility to encrypt the drive but it will not mount to my desktop. I re-formatted using the G technology raid configuration utility and then went in to erase through disk utility and it does not offer an encryption choice. Any and all help would be greatly appreciated.

Thank you!