Valueline RO 4-Cartridge Replacement Filter Set
This kit contains the four replacement cartridges used by a 5-stage Valueline reverse osmosis system: one 5-micron sediment prefilter, two carbon block prefilters, and one inline GAC postfilter. Together they cover every filter stage on the system except the RO membrane, which is sold separately and replaced on a longer cycle.
How the 5 Stages Work — and What's in This Kit
5 Micron Sediment Prefilter
Captures particulate, silt, rust, and suspended solids before they reach the carbon stages or the membrane.
Carbon Block Prefilter
Reduces chlorine, VOCs, and organic compounds that would otherwise oxidize and shorten the life of the RO membrane.
Second Carbon Block Prefilter
A second pass of carbon block filtration for additional chlorine and organic reduction, giving the membrane the cleanest possible feed water.
Reverse Osmosis Membrane
The membrane does the dissolved-solids reduction. It is not part of this kit and is typically replaced every 2–3 years rather than annually.
Inline GAC Postfilter
Final taste and odor polish on the permeate line, with 1/4" FPT connections for direct inline installation.
Filter Kit Details
Component Breakdown
| Sediment Prefilter | 1 × 5 micron spun polypropylene cartridge |
| Carbon Block Prefilters | 2 × activated carbon block cartridges |
| Inline Postfilter | 1 × granular activated carbon (GAC) inline with 1/4" female pipe thread |
| Total Cartridges | 4 (RO membrane not included) |
| Replacement Interval | Prefilters and postfilter: 12 months | Membrane (not included): 24–36 months |
| Operating Temperature | 40–100°F (4–38°C) typical municipal water range |
| Housing Compatibility | Standard 10" filter housings on Valueline RO systems |
| Installation Note | Transfer existing fittings from old inline postfilter to new unit using Teflon tape |
Pro Tip: When swapping the inline postfilter, carefully remove the push-connect or threaded fittings from your old filter and apply fresh Teflon tape before threading onto the new cartridge. Hand-tighten only to avoid cracking the filter housing, and flush the new GAC postfilter for 5 minutes to clear carbon fines before normal use.
When to Change What
Sediment Prefilter
Sooner on well water or high-turbidity supply
Both Carbon Blocks
Replace as a pair to keep chlorine off the membrane
Inline GAC Postfilter
Change annually or whenever taste falls off
RO Membrane
Not included — ordered separately
System Match and Use Cases
This kit is specifically dimensioned for 5-stage Valueline reverse osmosis systems and supplies all four prefilter and postfilter cartridges required for one year of operation. The sediment prefilter protects the downstream stages from particulate fouling, while the two carbon block prefilters remove chlorine and organic compounds that can oxidize and damage the RO membrane. The inline GAC postfilter connects directly into the permeate line using 1/4" female pipe thread fittings, delivering final taste and odor polishing before the faucet. The RO membrane itself is not included in this kit and typically requires replacement every 2–3 years depending on source water quality and system usage. Ideal for residential point-of-use applications where municipal or well water feeds the Valueline RO platform.
Ships from California
Stocked and shipped from our own warehouse for fast delivery.
Complete Annual Set
All four replaceable cartridges in one order — no partial kits.
Build Help
Not sure which stage is which? Call (877) 541-6603.
