How Often Should You Change Your Water Filter?
Quick Answer
You should change your water filter every 2 to 6 months, depending on the filter type and your household water usage. Most standard pitcher filters need replacing every 2 months, while under-sink filters can last up to 6 months.
Nobody thinks about their water filter until the water tastes wrong. The problem is, by then you've been drinking unfiltered water for weeks. A filter that's past its prime isn't just ineffective — it can actually release trapped contaminants back into your water.
Detailed Breakdown
The right replacement schedule depends on what type of filter you're using, how many people are in your household, and the quality of your tap water.
By Filter Type
Pitcher filters (Brita, PUR, ZeroWater) Replace every 2 months (about 40 gallons). If you have a large family or fill it multiple times a day, you may need to replace it more often — every 4-6 weeks.
Fridge filters (built-in refrigerator filters) Replace every 6 months. Most fridges have a replacement indicator light, but these are based on time, not actual usage — so if you use a lot of water, go by taste and flow rate instead.
Under-sink filters (reverse osmosis, carbon block) Replace the sediment and carbon pre-filters every 6 months. The RO membrane itself lasts 2-3 years. Check your system's manual for the specific schedule.
Faucet-mounted filters (PUR, Brita faucet mount) Replace every 2-3 months or every 100 gallons, whichever comes first.
Whole-house filters Replace every 3-6 months depending on sediment levels and water source. Well water users may need more frequent changes.
Signs It's Time
Even if you're not sure how long it's been, these signs mean your filter needs changing now:
- Water flow has slowed noticeably
- Water has an unusual taste or odor
- The filter indicator light is on (if your system has one)
- Water appears cloudy after filtering
- You genuinely can't remember when you last changed it
Quick Reference Table
| Filter Type | Replace Every | Notes | |-------------|---------------|-------| | Pitcher (Brita/PUR) | 2 months | More often for large households | | Fridge filter | 6 months | Go by taste if heavy usage | | Under-sink carbon | 6 months | RO membrane: 2-3 years | | Faucet-mounted | 2-3 months | Or every 100 gallons | | Whole house | 3-6 months | Well water = more frequent |