Stefani water filter cartridges: the right replacement for each Stefani jug, tap, under-sink, ceramic and whole-house unit

Stefani is the water filter brand on the Bunnings shelf, and the shelf is where the confusion starts: a row of boxes labelled “250 mm universal”, “gravity fed candle” and “whole of house” with no sign saying which goes in the unit you own. This page matches each cartridge to its unit and prices it, from the Bunnings pages we loaded on 1 November 2026. The short version: jugs take the $8.50 cartridge or the $8 PureFlow, under-sink systems take 250 mm cartridges ($8.85 sediment, then $38.40 or $58.50 carbon), ceramic purifiers take one of three candles ($27.40 to $36.90), the 20 inch whole-house twin takes a $135 carbon block, and the RO system takes a $124 membrane.

Which Stefani cartridge fits which unit?

Go by the size in the name, not the picture. 250 mm (10 inch) universal cartridges fit the Stefani single, twin and triple under-sink systems, the undercounter RO’s pre-filter housings and the On-Bench Digipure, and the Bunnings listings say so for each; they also fit any other brand’s standard 10 x 2.5 inch housing. 4.5 x 10 inch and 4.5 x 20 inch cartridges fit the whole-house big-blue twins and triples. Gravity fed candles fit the ceramic purifiers (10 L, 15 L and the terracotta and stainless models) and screw into the upper chamber. PureFlow and jug cartridges drop into the jugs and the Pure Flow 8.5 L dispenser. The inline caravan cartridge is its own unit with hose fittings, and the RO membrane fits the undercounter 5-stage system. The on-tap cartridges ($17 and $20 on Stefani’s site, Bunnings only) fit the On Tap system.

Under-sink: which second stage should you buy?

The first stage is always the $8.85 5 micron sediment cartridge; it’s cheap because its job is to catch grit before the carbon. The choice is the second stage. The 1 micron green carbon ($38.40) is granular coconut carbon, which Stefani says has chlorine reduction “tested and verified by independent laboratory”, and it’s the cartridge the twin ships with: buy it if chlorine taste is the complaint, which in Sydney, Melbourne and Brisbane it usually is. The 0.5 micron ultra fine ($58.50) is the upgrade: its listing claims lead, cysts, turbidity and chlorine taste and odour, which is the cartridge for old copper plumbing, a tank, or anyone who wants the finer block. Neither listing names the laboratory or an NSF listing, so these are Stefani’s claims; the under-sink guide explains why the Philips FastFlow is our pick when certified PFAS reduction matters.

On running cost, the twin on the standard pair is about $62 a year changed twice; on the ultra fine, about $135. Bunnings also lists a 0.2 micron all-carbon cartridge ($59.54), a 0.6 micron extra-long-life block ($39.90), a 2 micron ($35.90) and a 25 micron sediment ($11.50), all 250 mm, if you want to tune the stages.

Ceramic purifiers: three candles, one shell

All three gravity candles use a ceramic outer shell with carbon inside and colloidal silver, which Stefani says helps inhibit bacterial growth in the candle. The Aqua Balance ($27.40) claims chlorine, taste, odour and sediment and keeps the minerals. The Aqua Endura ($32.50) swaps loose carbon for a carbon block core and is sold as the long-life candle for households that drink a lot. The Aqua Elite ($36.90) adds lead, heavy metals and PFAS (PFOA/PFOS) reduction to the claims. None of the three listings gives a micron rating, a litre life or the models it fits, and Stefani’s site had no candle page we could load, so buy by thread and by claim: the Elite for $4.40 more than the Endura is the one we’d put in a 10 L ceramic. Scrub the ceramic with a soft brush every few weeks, which the benchtop guide covers, and replace on the maker’s schedule, which Stefani doesn’t print; six months is the common figure for carbon candles.

Jugs, whole house, RO and caravan

The jug cartridge at $8.50 is rated to 150 L and fits “Stefani jugs and most popular brands”; the PureFlow 3-pack at $24 is $8 a cartridge, rated to 150 L or four weeks, with claims of over 98% chlorine reduction plus zinc, cadmium, mercury and copper, lead-free materials to NSF/ANSI 372, and a fit for Brita and Philips jugs by the Bunnings listing. If that fit claim holds in your jug, it’s the cheapest 150 L cartridge on this site; our Brita cartridge guide sets out what the genuine Maxtra Pro claims that a substitute doesn’t.

The 20 inch 0.5 micron carbon block at $135 (special order) is the second stage of the Stefani 20 inch twin we recommend in the whole-house guide; pair it with Stefani’s 20 inch sediment cartridges (5 micron pleated $64, 1 micron polyspun $69.98, 10 micron $45) or any other brand’s 4.5 x 20 inch cartridge, because big blue is a standard size. The RO membrane at $124 is the one Bunnings sells for the undercounter 5-stage system; its listing gives no GPD, rejection or life figure and reads like a sediment cartridge’s description, so ask Stefani for the data sheet before you trust it on fluoride. The inline caravan cartridge at $29.98 is a complete unit with 12 mm click-on hose fittings, rated at 5,000 L or 12 months, for microbiologically safe water only by its own listing; the caravan guide compares it with the Frizzlife and All Set units.

The one trap

Buying the cheapest 250 mm cartridge twice. The $8.85 sediment cartridge and the $38.40 carbon look alike on the shelf and both say “universal”; a twin with two sediment cartridges filters grit and nothing else, and a twin with two carbons clogs the first one with grit in a month. Sediment first, carbon second, and write the change date on the housing.

What we left out and why

• Stefani 4.5 x 10 inch whole-house cartridges (Bunnings, $23.98 to $73.06). The 10 inch twin and triple’s cartridges; the same logic as the 20 inch, in the smaller size.
• Stefani on-tap digital and on-tap ceramic cartridges. Stefani’s site lists them at $17 and $20 and says Bunnings only; Bunnings’ search didn’t return them on the day.
• Stefani Electrolux fridge filter ($53.05) and universal inline fridge filter ($31.90). Covered by the fridge filter guide’s logic: match the part number.
• Stefani anti-scale resin cartridges (10 and 20 inch). In the water softener guide.
• Stefani 1.0 micron quick-change cartridge ($59.98) and high flow 5 micron ($61). Proprietary to the quick-change and high-flow systems, which Bunnings sells as special orders.
• Amazon Australia Stefani listings. Amazon sells several of these cartridges (the 5 micron carbon block, the 0.5 micron lead reduction, the candles, the PureFlow packs); we’ll add buttons as we confirm each listing matches the Bunnings part.