I don’t think it’s about if it’s a “good” carbon. NTM will just thrive in any carbon filters them apparently.

I saw somewhere on some thread Dr F mentioned changing Lifestraw carbon filter every 3 weeks, But im not sure why we would need to since lifestraws carbon is AFTER microfilter and thus shouldn’t have much or any NTM ?
On the other hand, RO carbons are before the 0.001 filter so those carbon filters will have NTM and must be changed but HOW often? Anyone know?

THIS begs the question do we need to change Lifestraws microfilter MORE OFTEN than company says to for non-NTM/BE people? Because that filter definitely would have the NTM. Oy