Davey Microlene 20" Jumbo Twin Filter Housing - WaterMark Certified, High Flow, Dual Stage NZ

The Davey Microlene AS20J is a dual-stage 20" jumbo filter housing built for large homes, lifestyle blocks, and high-demand supplies. Running two 20" jumbo cartridges in sequence, it delivers high dirt-holding capacity and strong flow rates — up to 155 lpm — with very little pressure loss across the system.

Certified to WaterMark WMTS-103 (Lic. 032114) and tested in compliance with AS/NZS 4020 for use in contact with drinking water. Manufactured under ISO 9001 quality management and ISO 14001 environmental management systems.

Available as a housing only, or with cartridges matched to your water source — select from the dropdown.

Includes housing spanner and bracket fixings.

Bore water quality varies significantly. We recommend testing your bore water before selecting a filtration system — get in touch and we'll help you choose the right configuration for your supply.

Key specs at a glance

• Cartridge size: 20" jumbo (114mm / 4.5" diameter)
• Ports: 25mm (1") female BSP
• Dimensions: 717mm H × 410mm W
• Recommended max flow: 155 lpm
• Max pressure: 880 kPa (128 psi)
• Water temperature: 0–40°C
• Max ambient temperature: 50°C
• Material: Glass reinforced polypropylene
• Pressure relief valves: Yes (both bowls)
• Warranty: 1 year (housing)
• WaterMark WMTS-103, Lic. 032114
• Tested to AS/NZS 4020

Why Kiwi homeowners choose Davey Microlene

• WaterMark certified and AS/NZS 4020 tested — verified for drinking water contact
• 20" jumbo cartridges deliver roughly twice the dirt-holding capacity and service life of 10" equivalents
• 155 lpm flow rate — handles whole-house demand on large properties without pressure drop
• Glass reinforced polypropylene construction — built for demanding conditions
• Pressure relief valves on both bowls for safe, easy cartridge changes
• 1-year warranty backed by Davey's NZ dealer network

What do the certifications mean?

WaterMark WMTS-103 (Lic. 032114): Independently tested and certified against Australian and New Zealand water industry standards for plumbing products.

AS/NZS 4020: Tested in compliance with the standard for products used in contact with drinking water — covering materials, construction, and potential effects on water quality.

ISO 9001: The manufacturer operates a certified quality management system.

ISO 14001: The manufacturer operates a certified environmental management system.

Choosing your variant

Housing only (AS20J)
Both bowls ship empty. Choose this if you want to specify your own cartridge combination, or if you're replacing an existing housing.

Rainwater and tank water kit (KAS20J) — for tank, rainwater, and bore supplies
Stage 1: 20PP20J — 20 micron poly pleated. Catches coarse sediment, dirt, rust, and leaf matter. Clean every 3–6 months, replace every 12 months.
Stage 2: 1PS20J — 1 micron poly spun. Removes fine particles and physically blocks parasitic cysts. Replace every 6–12 months.

Mains water kit (KAS20JM) — for town supply
Stage 1: 5PS20J — 5 micron poly spun. Removes fine sediment from mains supply. Replace every 6–12 months.
Stage 2: ACB20J — 5 micron carbon block. Reduces chlorine taste and odour. Replace every 6–12 months, or earlier if taste returns.

Not sure which kit suits your water? Get in touch and we'll help you choose.

Full technical specifications

Specification	AS20J	KAS20J	KAS20JM
Connections	25mm (1") female BSP
Max flow	155 lpm
Max pressure	880 kPa (128 psi)
Water temperature	0–40°C
Max ambient temperature	50°C
1st stage cartridge	None	20PP20J (20 micron)	5PS20J (5 micron)
2nd stage cartridge	None	1PS20J (1 micron)	ACB20J (5 micron)
Height	717mm
Width	410mm
Material	Glass reinforced polypropylene
Pressure relief valves	Yes — both bowls
Inclusions	Housing spanner, bracket fixings
Certifications	WaterMark WMTS-103 (Lic. 032114), AS/NZS 4020
Quality systems	ISO 9001, ISO 14001
Warranty	1 year (housing)

What's in the box

All configurations:

• 1 × Davey Microlene 20" jumbo twin filter housing (AS20J)
• Housing spanner
• Bracket fixings

Rainwater and tank water kit (KAS20J) also includes:

• 1 × 20PP20J — 20 micron poly pleated sediment filter
• 1 × 1PS20J — 1 micron poly spun sediment filter

Mains water kit (KAS20JM) also includes:

• 1 × 5PS20J — 5 micron poly spun sediment filter
• 1 × ACB20J — 5 micron carbon block filter

FAQ

What size cartridges does this housing take?

It takes 20" jumbo cartridges — 4.5" (114mm) outside diameter. Standard or 10" cartridges will not fit.

What's the advantage of 20" jumbo cartridges over 10" jumbo?

The 20" format holds roughly twice the media volume. That means higher dirt-holding capacity, less frequent replacements, and better flow rates on high-demand supplies. For large homes and lifestyle blocks, the 20" is the right choice.

What does WaterMark certification mean?

WaterMark (WMTS-103, Lic. 032114) means the housing has been independently tested and certified to meet NZ and Australian plumbing standards.

What does AS/NZS 4020 mean?

It means the housing has been tested for use in contact with drinking water — covering the materials used and their effect on water quality.

Which kit should I choose — KAS20J or KAS20JM?

KAS20J is for tank, rainwater, and bore supplies where sediment and cyst removal are the priority. KAS20JM is for town (mains) supply where chlorine taste and odour are the concern. If you're unsure, get in touch and we'll help you choose.

Can I install two units in parallel for even higher flow?

Yes. Davey recommends installing two kits in parallel when flow requirements exceed what a single unit can deliver.

Can I clean the Stage 1 cartridge in the rainwater kit?

Yes. The 20 micron poly pleated cartridge is cleanable. Rinse under a tap every 3–6 months and replace annually, or earlier if it no longer recovers after cleaning.

Why does it have pressure relief valves?

Each bowl has its own pressure relief valve. Press it before unscrewing the bowl to safely release water pressure — makes cartridge changes cleaner and easier.

Do I need a plumber to install it?

It connects via standard 25mm (1") BSP fittings. Most customers use a licensed plumber for whole-house installations. Get in touch if you're unsure what's involved for your setup.

What warranty applies?

The housing carries a 1-year warranty. Cartridges are consumable items and are not covered by warranty, but get in touch if anything arrives damaged or defective.