MD3600i - how to move disks from Disk Group to Disk Pool

I have Md3600i with two shelves MD1200

One MD1200 was created as Disk Group Raid 6

I am no longer using this space & would like to re-assign all the disk (12 x 1 Tb) to existing Disk Pool (12 x 2 Tb)

Is that possible/advisable?

Or shall I just create another Disk Pool instead?

Thanks

Seb