Whether you own a ROES-50, ROES-PH75, or another APEC model, the filter replacement schedule follows the same pattern. Here's the full timeline and how to manage it.
| Stage 1: PP Sediment | Every 6–12 months |
| Stage 2: GAC Carbon | Every 12 months |
| Stage 3: Carbon Block | Every 12 months |
| Stage 4: RO Membrane | Every 2–3 years |
| Stage 5: Post-Carbon | Every 12 months |
| Stage 6: pH+/Alkaline (ROES-PH75 only) | Every 12 months |
A TDS meter is the most reliable way to know when your RO membrane needs replacing:
Test your output monthly once your system passes the 2-year mark. TDS meters cost $10–$20 and remove the guesswork entirely.
| ROES-50 annual filters (no membrane year) | $60–$80 |
| ROES-50 membrane replacement year | $100–$130 total |
| ROES-PH75 annual filters (adds pH+ cartridge) | $70–$90 |
| Average cost over 3-year cycle | ~$75–$95 per year |