Aggregate size on a FAS3210

Running OnTAP 8.1.1, a FAS3210 has an upper aggregate limit of 50TB. This can be raised to 75TB with an upgrade to 8.1.2+ but consider that this is not an option, the current aggregate displays the following info:

toaster> df -Ah

Aggregate                total       used      avail capacity 

aggr0                     47TB       45TB     1878GB      96% 

aggr0/.snapshot            0TB        0TB        0TB     ---%

toaster> df -A

Aggregate               kbytes       used      avail capacity 

aggr0               50770751616 48801132908 1969618708      96% 

aggr0/.snapshot              0          0          0     ---%

As you can see the human-readable output formats the space to 47TB, but the kybes displayed when you don't summarize it show it at 50770751616. If you run the math on it you see the aggregate at 47.2TB.

Assuming I have space in a raid group to add to this aggregate is it possible for me to add 2-3 1TB disks to get this to 50TB, or is it already at the threshold according to the system?

I would very much like to grow this aggregate a bit to free up some space with the flexvols below.

Thanks in advance.