Dell MD3620F

Hi we have a MD3620f storage array, we currently have 12 hard drives in the system with two different Raid configurations across the drives.

I would like to add some additional hard drives into the system, can I do this while the system is live and once added can I add them to one of the addtional Raid 5 arrays without causing any issues to the data that is already contained on the existing disks?

Thanks