Am I at capacity on my NAS?

[carsn]

Hello!

I have a 5-bay F5-221 Terramaster NAS. It is currently setup with all 5-bays in use. I've slowly over past year or two been upgrading each bay to a larger capacity drive.

Currently it's a 6TB + 12TB + 18TB + 16TB + 16TB at total space of 68TB, with usable space of ~40TB. My last upgrade though, the 12TB I swapped out a 6TB for, I saw no storage upgrade after the RAID sync completed.

I am contemplating upgrading the last 6TB drive with an 18TB drive.

So now I'm at a bit of a standstill of, do I upgrade the other 6TB drive to 18TB (I believe the NAS supports a max of 80TB), or is this NAS at capacity and I am not going to get more space out of it?

Do you know how much space I'd get if I did upgrade to an 18TB drive for the 6TB drive?