Classic Pure Taiwan UDF Granular Activated Carbon Filter – 20-Inch Slim Cartridge (Stage 2) for Semi Commercial RO Plants
The Classic Pure Taiwan UDF Granular Activated Carbon Filter (20" Slim) brings the same trusted Stage 2 filtration as Axtron's established 10" UDF cartridge, sized for semi commercial RO plants and slim-housing water filter systems that need higher filtration capacity than a standard domestic setup.
This is a slim cartridge — 2.5" in diameter, the same width as the 10" domestic version, doubled in length to 20". As with our 20" CTO carbon block filter, this is built specifically for slim 20-inch housings, not jumbo/Big Blue 4.5"-diameter housings — an important distinction to check before ordering.
What UDF (Granular Activated Carbon) Removes
Unlike the compressed carbon block (CTO) used in Stage 3, this UDF cartridge uses granular activated carbon — loose carbon media with a large total surface area, well suited to reducing heavier chlorine loads and specific chemical byproducts before water reaches the more fine-grained carbon block and RO membrane stages. This filter specifically targets:
- Chlorine — the most common taste/odor issue in Pakistani municipal (WASA) water
- Chloramine — a chlorine-based disinfectant byproduct increasingly used as an alternative to straight chlorination
- DBPs (Disinfection By-Products) — chemical compounds formed when disinfectants react with organic matter in water
- TCE (Trichloroethylene) — an industrial chemical contaminant sometimes found in groundwater
Key Features
- Slim 20" x 2.5" Sizing — Built for standard slim housings used in semi commercial RO systems.
- Granular Activated Carbon Media — Loose carbon structure suited to Stage 2, heavier initial chlorine/chemical reduction.
- Targets Chlorine, Chloramine, DBPs & TCE — Specific, verifiable removal targets rather than generic "chemicals."
- Protects Downstream Filtration — Reduces the chemical load reaching Stage 3 (carbon block) and the RO membrane.
- Made in Taiwan — From Classic Pure, the established brand behind Axtron's domestic filter lineup.
Why Semi Commercial Systems Need the 20" Slim Size
Semi commercial RO plants — schools, clinics, offices, restaurants, and small businesses — handle meaningfully more daily water volume than a home RO system without needing a full jumbo/Big Blue filtration stage. A 20" slim UDF cartridge roughly doubles the carbon mass and contact time of a standard 10" cartridge, in the same housing diameter most slim multi-stage systems already use — and pairs naturally with our 20" slim CTO carbon block filter as Stage 2 and Stage 3 of the same system.
Applications
- Semi Commercial RO Plants — Schools, clinics, offices, restaurants, and small business water systems.
- Slim Multi-Stage Filtration Setups — Any system using standard 20"x2.5" slim housings.
- Stage 2 Pre-Filtration — Ahead of a Stage 3 carbon block (CTO) filter and the RO membrane.
Installation & Maintenance
- Install as the 2nd stage filter, typically after sediment filtration and before the carbon block (CTO) stage.
- Flush for 3–5 minutes before first use.
- Replace approximately every 3–6 months depending on water quality and usage volume — semi commercial systems with higher daily throughput may need more frequent replacement.
- Ensure a snug, leak-free fit in the housing.
Why Axtron?
Axtron Pakistan has supplied water filtration and RO plant components since 2005, with offices in Lahore, Multan, and Bahawalpur and a network of 500+ retailers nationwide. This 20" slim UDF extends our established Classic Pure Taiwan carbon filter line — pairing directly with our 20" slim CTO filter to give semi commercial customers a complete higher-capacity Stage 2 + Stage 3 filtration setup.
Conclusion
If you're running a semi commercial RO plant or any slim-housing water filtration system in Pakistan, the Classic Pure Taiwan UDF 20" Slim Granular Carbon Filter gives you the same trusted Stage 2 performance as our 10" filter, scaled up for higher-volume use.
8. Full Technical Specification Chart
| Parameter | Detail |
|---|---|
| Brand | Classic Pure |
| Filter Type | Granular Activated Carbon (UDF) |
| Stage | Stage 2 in multi-stage RO/filtration systems |
| Removes | Chlorine, chloramine, DBPs, TCE |
| Size | 20" x 2.5" (Slim) |
| Housing Compatibility | Standard slim 20" housings (not jumbo/Big Blue 4.5" diameter) |
| Made in | Taiwan |
| Service Life | Approx. 3–6 months, depending on water quality and usage volume |
| Applications | Semi commercial RO plants, slim-housing filtration systems |
| Price | ₨1,000 |
Material composition: listed generically as "granular activated carbon" pending confirmation of the specific carbon source (see accuracy note above).
9. Features → Benefits Chart
| Feature | Benefit to the Customer |
|---|---|
| Slim 20" sizing | Higher filtration capacity without switching to jumbo housings |
| Granular carbon media | Effective at absorbing heavier initial chlorine/chemical loads |
| Targets chloramine, DBPs, TCE | Specific, verifiable contaminant removal, not just generic "chemicals" |
| Stage 2 protection | Reduces chemical load reaching Stage 3 carbon block and RO membrane |
| Made in Taiwan | Same trusted manufacturing as Axtron's established 10" UDF filter |
10. 10" vs. 20" Slim UDF — Quick Comparison
| Classic Pure UDF 10" | Classic Pure UDF 20" Slim | |
|---|---|---|
| Diameter | 2.5" | 2.5" |
| Length | 9.75" | 20" |
| Best for | Domestic RO systems, homes & offices | Semi commercial RO plants, higher-volume use |
| Housing type | Standard slim housing | Standard slim housing (taller) |
| Price | ₨500 | ₨1,000 |
11. Delivery & Service Coverage of Classic Pure Taiwan UDF
| City | Coverage |
|---|---|
| Multan | Axtron office (Near Lakar Mandi Chowk, Railway Road) |
| Lahore | Axtron office (91-A Feroz Pur Road) |
| Bahawalpur | Axtron office (Opp. Sadiq Public School, Ahmad Pur East Road) |
| Karachi, Islamabad, Rawalpindi, Faisalabad | Nationwide delivery (no physical branch) |
12. FAQ Section (add via Rank Math's FAQ block for FAQPage schema)
Q1: What's the difference between this UDF filter and your CTO filter?
A1: UDF uses loose granular activated carbon and is typically installed as Stage 2, handling the initial, heavier chlorine and chemical load. CTO is a compressed carbon block used as Stage 3, providing finer polishing filtration before the RO membrane. Many systems use both in sequence.
Q2: What does this filter remove?
A2: Chlorine, chloramine, disinfection by-products (DBPs), and TCE (trichloroethylene), along with general odor and taste improvement.
Q3: Will this fit a jumbo 20" housing?
A3: No — this is a "slim" cartridge, 2.5" in diameter, the same width as a standard 10" filter. Jumbo (Big Blue) housings use a 4.5" diameter and need a different cartridge.
Q4: What system is this designed for?
A4: Semi commercial RO plants and any multi-stage filtration system using standard 20"x2.5" slim housings.
Q5: How often should I replace it?
A5: Roughly every 3–6 months, depending on water quality and usage. Semi commercial systems with higher daily throughput may need more frequent replacement.
Q6: Do you deliver this across Pakistan?
A6: Yes — Axtron delivers nationwide, including Karachi, Lahore, Islamabad, Rawalpindi, Faisalabad, and Multan, with physical offices in Lahore, Multan, and Bahawalpur.

