i have 5 bay synology NAS and as my 5x hdds (non nas drives) are now between 5-6 years old, maybe its time to get proper NAS hdds or at least spare just in case one is failing.
i only need 4 good hdd (1 in my nas is for torrenting purposes dont care about data loss).
use code pick20up from https://www.ozbargain.com.au/node/333311
few choices here, probably few $ more expensive than ozb record lowest ever, but not bad.
futuonline
Western Digital WD Red 4TB 3.5" SATA Internal NAS Hard Drive HDD 5400RPM 64MB
http://www.ebay.com.au/itm/Western-Digital-WD-Red-4TB-3-5-SA…
$188
warehouse1
Seagate ST4000VN008 IronWolf Hard Drive 4TB
http://www.ebay.com.au/itm/Seagate-ST4000VN008-IronWolf-Hard…
$167
shopping-express-clearance
Western Digital WD RED 4TB
http://www.ebay.com.au/itm/Western-Digital-WD-BLUE-RED-1TB-2…
$188
shopping-express-clearance
Western Digital WD RED 3TB
http://www.ebay.com.au/itm/Western-Digital-WD-BLUE-RED-1TB-2…
$135
winner here is the seagate 4TB but for me four of 3TBs (equal to 9TB space after synology SHR/RAID) is enough.
the more space you have the more junk you will put into.
Good price for WD red 3TB. Thanks OP.