Replace your pool filter cartridge once a year.

Yes, yearly is the right interval for most residential pools.

Cartridges wear out. Even if you rinse them regularly, the fibers break down, pores clog permanently, and flow drops. After a year, you’re losing efficiency. Your pump works harder, your water gets less filtration, and you end up using more chemicals to compensate.

Some people stretch it to two seasons. That works if you have a light-use pool, clean it obsessively, and replace only when pressure spikes. But for the average backyard pool with regular swimming, one year gives you the best balance of cost and performance. A replacement is usually $30–$60. That’s cheap insurance.

Don’t wait until the cartridge looks frayed or falls apart. By then you’ve already been running a half-clogged filter for weeks. Just put a calendar reminder and swap it out annually at the start of the season.

Your pump will thank you.