Four cartridges
Stages 1, 2, 4, and 5
Includes the sediment prefilter, T28 coconut carbon prefilter, T33 coconut carbon post-filter, and 3-in-1 alkaline cartridge.
4-Filter Replacement Set for 5-Stage Alkaline Countertop RO Systems — Sediment, T28, T33 & 3-in-1 Alkaline with 8 Fittings — SKU 4FILTERAT1
Price range: $54.00 through $119.00
4 Filter Set for 5-stage Alkaline Countertop RO Systems, including Sediment, T28, T33 and 3-in-1 Alkaline inline filter cartridges. SKU# 4FILTERAT1
- Description
- Additional information
- Reviews (1)
Description
4-filter maintenance set for 5-stage alkaline countertop RO
Sediment, T28 carbon, T33 post-carbon, and 3-in-1 alkaline cartridges with eight replacement fittings
This maintenance set is designed for compatible 5-stage alkaline portable and countertop reverse-osmosis systems using inline quick-connect filters. It replaces the four non-membrane filtration cartridges and includes eight replacement fittings for renewing the inlet and outlet connections during service.
4 filtersAll non-membrane cartridges
8 fittingsReplacement connections included
10″ × 2″Inline cartridge format
No membraneRO membrane sold separately
Routine system maintenance
Replace the sediment, carbon, and alkaline stages without changing the RO membrane
This set is intended for the regular service interval when the four inline cartridges need replacement but the existing RO membrane is still producing the required rejection. Replacing the complete non-membrane set helps restore flow, chlorine pretreatment, membrane protection, taste polishing, and final mineral or pH adjustment.
Service hardware
Eight Replacement Fittings
Includes two replacement fittings for each inline cartridge, allowing the inlet and outlet connections to be renewed during installation.
Four replacement filters
Particle protection, carbon pretreatment, taste polishing, and alkaline treatment
1
5-Micron Sediment Filter
Helps capture rust, sand, dirt, and suspended particles before they reach the carbon filter and RO membrane.
2
T28 Coconut Carbon Filter
Helps reduce chlorine, taste, odor, and selected organic compounds while helping protect the RO membrane.
4
T33 Coconut Carbon Filter
Provides final taste and odor polishing after reverse osmosis and before the alkaline stage.
5
3-in-1 Alkaline Post-Filter
Contains alkaline mineral, ORP-related ceramic, tourmaline, and calcite media. It may add selected minerals and increase the pH of acidic RO water.
Package contents
Filters and replacement fittings included
- ✓1 × 5-micron inline sediment filter
- ✓1 × T28 coconut-shell activated carbon prefilter
- ✓1 × T33 coconut-shell activated carbon post-filter
- ✓1 × 3-in-1 alkaline post-filter
- ✓8 × replacement fittings
Key benefits
A complete non-membrane service set for the 5-stage alkaline system
Four Matching Filters
Replaces all non-membrane cartridges in a compatible five-stage alkaline countertop RO system.
Sediment Protection
Helps protect the carbon stage and RO membrane from suspended particles.
Chlorine Pretreatment
The T28 carbon stage helps reduce chlorine before water reaches the membrane.
Alkaline Post-Treatment
The final cartridge may add selected minerals and increase the pH of acidic RO water.
Eight New Fittings
Provides replacement inlet and outlet fittings for all four cartridges.
Inline Quick-Connect Format
Designed for compatible classic countertop systems using 1/4″ tubing connections.
Specifications
Verified cartridge details
| Product type | Four-filter maintenance set for 5-stage alkaline countertop RO systems |
|---|---|
| Compatible system type | Selected portable and countertop RO systems using sediment, T28, RO membrane, T33, and 3-in-1 alkaline stages |
| Sediment filter | 5 micron, approximately 10″ × 2″, 1/4″ female ports |
| Sediment manufacturer SKU | IL-10W-S514 |
| Carbon prefilter | T28 coconut-shell activated carbon, approximately 10″ × 2″, 1/4″ female ports |
| T28 manufacturer SKU | CL10ROT28-B |
| Post-carbon filter | T33 acid-washed coconut-shell carbon, approximately 10″ × 2″, 1/4″ female ports |
| T33 manufacturer SKU | IL-10W-C |
| Alkaline post-filter | 3-in-1 alkaline cartridge, approximately 10″ × 2″, 1/4″ female ports |
| Alkaline manufacturer SKU | MAF-3in1 |
| Listed alkaline media | Alkaline mineral, ORP-related ceramic, tourmaline, and calcite media |
| Replacement fittings | 8 pieces included |
| Filter quantity | 4 cartridges total |
| RO membrane | Not included |
| Listed package dimensions | 10 × 10 × 2 in on MyAquaFilter; 12 × 6 × 6 in on MyWaterClub |
| Listed package weight | 56 oz on MyAquaFilter; 4–5 lb on MyWaterClub |
| Primary MyAquaFilter SKU | 4FILTERAT1 |
| Compatible SKUs | 4FILTERAT, 4FILTERAT1, and 4FILTERAT2 |
Typical replacement schedule
- ✓Sediment filter: replace based on flow, discoloration, sediment load, or the system schedule
- ✓T28 carbon filter: approximately 8–12 months or up to 1,500 gallons, depending on water quality and usage
- ✓T33 carbon filter: approximately 8–12 months or up to 1,500 gallons, depending on water quality and usage
- ✓3-in-1 alkaline filter: approximately 8–12 months or up to 1,000 gallons, depending on water quality and usage
- ✓RO membrane: inspect separately and replace based on age and measured rejection
Compatibility checklist
Confirm the existing system before ordering
✓
Five-stage alkaline configuration
The system should use sediment, T28 carbon, RO membrane, T33 carbon, and 3-in-1 alkaline stages.
The system should use sediment, T28 carbon, RO membrane, T33 carbon, and 3-in-1 alkaline stages.
✓
Inline 1/4″ tubing connections
Confirm that the existing cartridges use compatible 1/4″ tubing and removable fittings.
Confirm that the existing cartridges use compatible 1/4″ tubing and removable fittings.
✓
Existing membrane still performs properly
This maintenance set does not include a replacement RO membrane.
This maintenance set does not include a replacement RO membrane.
✓
Correct stage order
Install each cartridge according to its flow arrow and original position in the system.
Install each cartridge according to its flow arrow and original position in the system.
Replacement guidance
Plan approximately 30–40 minutes for the filter change
1
Shut Off and Depressurize
Disconnect the system from the faucet and allow pressure to dissipate before removing tubing or fittings.
2
Record the Tube Routing
Photograph and label each tube before disconnecting the old cartridges.
3
Replace One Filter at a Time
Match each flow arrow and stage position, then install the supplied replacement fittings.
4
Flush and Check for Leaks
Pressurize slowly, inspect every connection, and flush the new carbon and alkaline filters before using the water.
Before purchase
Good to know
!
RO membrane is not included
This set replaces the four non-membrane cartridges only.
This set replaces the four non-membrane cartridges only.
!
Wrench is not included
A membrane-housing wrench is unnecessary for this cartridge-only maintenance set.
A membrane-housing wrench is unnecessary for this cartridge-only maintenance set.
!
Alkaline results vary
Final pH, TDS, mineral release, and ORP depend on source-water chemistry, flow, contact time, and cartridge condition.
Final pH, TDS, mineral release, and ORP depend on source-water chemistry, flow, contact time, and cartridge condition.
!
TDS may increase after the final stage
A higher reading can be expected because the alkaline cartridge adds dissolved mineral material after reverse osmosis.
A higher reading can be expected because the alkaline cartridge adds dissolved mineral material after reverse osmosis.
!
Flush before use
New carbon and alkaline media require thorough flushing before taste, TDS, and pH readings stabilize.
New carbon and alkaline media require thorough flushing before taste, TDS, and pH readings stabilize.
!
Photo must show all included parts
The updated product image should display all four cartridges and all eight replacement fittings.
The updated product image should display all four cartridges and all eight replacement fittings.
This product includes four replacement filter cartridges and eight replacement fittings. It does not include an RO membrane, membrane housing, wrench, frame, clips, tubing set, faucet adapter, or flow restrictor.
Not sure whether this set matches your alkaline countertop RO system?
Send the system model, filter labels, tubing size, and clear photos of the existing assembly before ordering.
Send the system model, filter labels, tubing size, and clear photos of the existing assembly before ordering.
Additional information
| Weight | 56 oz |
|---|---|
| Dimensions | 10 × 10 × 2 in |
| Choose | Assembly, Filter Set, Filter Set with new Quick Connect Fitting |
1 review for 4-Filter Replacement Set for 5-Stage Alkaline Countertop RO Systems — Sediment, T28, T33 & 3-in-1 Alkaline with 8 Fittings — SKU 4FILTERAT1
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Kevin S –
Recevied wrong set. Need exchange…