Skip ECC RAM for your non-critical NAS.

Probably not. ZFS is famously paranoid about data integrity, but for non-critical data—media libraries, game saves, old documents—the risk of a bit flip causing real damage is tiny compared to the cost premium of ECC.

ECC RAM costs more and limits your hardware choices to server-grade CPUs and motherboards. If you’re storing irreplaceable family photos or financial records, sure, go ECC. But for a small NAS running Kodi, Plex, or backup of things you could re-download? Non-ECC is fine. ZFS’s checksumming will catch most corruption anyway, and if a cosmic ray flips a bit in a movie file, you’ll never notice.

Spend the money on more storage or a good UPS instead.