there are a lot of frustrating tradeoffs with these kinds of filter pitchers. they can remove a lot of nasty solutes, but they can also introduce bacteria.

here's a study that found that brita-filtered water contained more bacteria than the tap water only a week into the filter's service life: https://pubmed.ncbi.nlm.nih.gov/8740859/

I used to be a religious brita user, but now I just stick to tap. hard to assess the relative risk, but it's cheaper than buying filters.