How often to replace 3M DS02 tap water filter?

I would guess after 6 months but who knows…

I came to the conclusion that these filters do nothing, and that they are just placebo, because tap water is perfectly drinkable but when you drink from the tap you think it’s dirty so you get sick, but when you use these filters you don’t, however even if you never changed them for years you still don’t get sick.

I think it’s this way with brita filters.