Hard disk Compatibility for NSA221

Recently, my NSA221, yes NSA221! showed a red light for my disk 1.  I checked the manual and it suggests that my harddrive is degraded.  Well, my NSA is still nice and good and I don't want to dump a workable (still) NSA and buy a new one.  Thus, I would like to buy a new harddisk to replace the degraded one.  It seems that the SATA-3 HD can downward compatible to SATA1 and 2.  I would wonder whether a SATA-3 harddisc, Ironwolf 1TB, can be used on my NSA? 

Thanks in advance.