The RCC7 uses a 5-stage filter set — different from the RCC7AK. Here's the right set to buy, the full schedule, and how to keep costs low.
The RCC7 uses 5-stage filter sets. The RCC7AK uses 6-stage sets that include the alkaline filter. They are different products — always confirm your model before ordering.
| Stage 1: PP Sediment | Every 6–12 months |
| Stage 2: GAC Carbon | Every 12 months |
| Stage 3: CTO Carbon Block | Every 12 months |
| Stage 4: RO Membrane | Every 2–3 years |
| Stage 5: Post-Carbon GAC | Every 12 months |
| Annual cost estimate | $50–$80 per year |
iSpring sells pre-packaged sets for easy annual replacement:
| F4 — 6-month set | Pre-filters only. For more frequent pre-filter changes. |
| F5 — 1-year set | All 5 stages for 12 months. Most popular. |
| F15 — 2-year set | Includes RO membrane. Best value per filter. |
A TDS meter is your best tool. RCC7 output should read 10–30 TDS from typical municipal water. Above 50 TDS suggests pre-filters or the membrane need attention. Follow the time-based schedule as a baseline.