Replacement Filters for the Tier1 20" Big Blue Kit Whole-House System
Tier1 20" Big Blue Kit
✅ Best value — replace everything at once
IPW 3-cartridge set — every replaceable stage in one order
✓ Guaranteed to fit your Tier1 20" Big Blue Kit
📋 Typical replacement: sediment every 3–6 months · carbon every 6–12 months
1
Pleated sediment 20 micron
20×4.5 Big Blue
Replaces OEM (replaces S1-20BB/155305-43)
2
GAC granular carbon
20×4.5 Big Blue
3
Carbon block 0.5 micron
20×4.5 Big Blue
Replaces OEM (replaces CBC-20BB/FLOPLUS-20BB)
Not sure this is your system? Use the Isopure Water Filter Finder → Match by system name, by the part number on your cartridge, or by photo.
