8
I guess it also depends on how many days you've configured an account to be considered "new".
Reason being, with lemm.ee shutting down at the end of this month, a lot of accounts are moving to other instances, so you'll probably be inadvertently filtering far more people than you intend.
When things are stable, it's a nice filter option to hide the whack-a-mole trolls who keep popping up, but when a major instance closes shop and/or there's some kind of mass-migration in progress, it can be detrimental.
