Most experts scream a simple number: every six to twelve months for the pre-filters and post-filter. The actual RO membrane? That’s a marathon runner. It lasts two to three years.
Think of it this way: your pre-filters are the bouncers at a club. They catch the big troublemakers (sediment, chlorine). They wear out fast. The membrane is the VIP lounge guard. It catches the sneaky, tiny villains (lead, arsenic). It’s tougher, but still needs a break.
The “Yuck” Factor Quiz
Here’s a fun, gross test. Fill a glass with your filtered water. Now fill one with tap water. Sniff both. Does your filtered water smell a little… swampy? That’s bad news bears.
That smell is bacteria throwing a party inside your old filter. Your RO system is supposed to stop that party. A swampy smell means it’s time to immediately replace everything.
