4 Stage Ultrafiltration Water Filter Under the sink
4 Stage Ultra Filtration Undersink Water Filter System
If you’re looking for undersink water filter systems that deliver fresh, pure water right from your kitchen, the Waco 4 Stage Ultra Filtration is designed to raise your expectations. Forget buying bottled water or worrying about odd tastes, this system brings four layers of under sink water purification to your home, your family, and every recipe you make.
How It Works: Four Layers, Real Results
- Stage 1 – Sediment Pre-Filter: This tough 5-micron filter is your first line of defense, capturing dust, rust, and suspended sediment so your water looks and pours clear every time.
- Stage 2 – Carbon Block: Tackles chlorine, stubborn odors, and organic compounds, removing the off-notes you notice (and the ones you don’t).
- Stage 3 – Ultra Filtration Membrane: With a 0.03 micron hollow fiber design, this stage specializes in bacteria removal—catching E-coli, giardia, viruses, colloids, and more. You get peace of mind with every glass.
- Stage 4 – Final Carbon Polish: The last stage ensures any remaining chlorine, chemical traces, or musty flavours are erased for good. Every cup tastes pure and fresh, whether you’re hydrating or cooking.
Smart, Space-Saving, and Simple
Waco designed this under sink water filter to fit the realities of modern kitchens. The compact, slimline system, it can be installed vertically or horizontally, so it never hogs your storage space or interferes with your bins. The patented color-coded cartridges twist in and out easily, meaning easy installation and no more complicated filter changes.
Tap Compatibility for Every Kitchen
Worried about fit? This system works perfectly with most 3 way taps, all filtered water taps, and of course, every MDC tap. All the fittings you need are in the box, including mini valve, pressure limiting valve, 2m of tubing.
- Note: This filtration system does not include a faucet by default. Please add a faucet or 3-way mixer to complete your setup. If you already have a compatible filter tap, you can skip this option.
Ideal for Renters, Caravans, or Outdoor Setups
Renters and travellers love how this system installs and uninstalls with zero damage, making it the top pick for caravan owners and outdoor kitchens. It goes wherever you do, so your water always stays pure.
Maintenance, Real Talk, and What to Expect
- Major components are NSF certified, but the system as a whole is not.
- Designed for use on biologically safe water supplies (municipal or pre-treated).
- Ultra fine filtration means a slightly slower flow compared to basic filters—but you get higher quality purification in return.
- Flush daily for 10 seconds before first use, 30 seconds after any 3-day gap, and 3–5 minutes after new cartridge install.
- Actual cartridge appearance may vary as we continue to improve the product.
Why Australian Families Trust MDC
With MDC, you get much more than just undersink water filter systems. Every unit comes with a 1-year warranty, 30-day money-back guarantee, and free shipping across Australia. Our team is here when you need us, so you can trust every drop.
Specs at a Glance:
- Filtration: 4-stage (sediment pre-filter, post carbon block, ultra filtration membrane, final carbon block)
- Micron rating: 5 micron (Stage 1), 0.03 micron (Stage 3)
- Size: 35 x 33 x 12 cm
- Cartridge life: 12 months
- Installation: Vertical or horizontal
- Tap compatibility: 3 way taps, filtered water taps, all 1/4" tubing taps
- Component quality: NSF certified materials
- Warranty: 2 year
- 14-day money-back guarantee
- Free shipping Australia-wide
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Estimated Delivery:Aug 28 - Sep 01
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Free Shipping
4 Stage Ultrafiltration Water Filter Under the sink
What People Are Saying
Izabella - VIC
A single mixer tap keeps the sink area tidy and easier to clean, and filters definitely work, because water tastes great and I haven't had to descale the kettle for months.
I purchased Short Square Neck Black and Stainless Steel 3 way Mixer Tap with Ultrafiltration+Alkaline+Carbon Cartridge Pack for our new kitchen. Very happy with the quality of the products. A single mixer tap keeps the sink area tidy and easier to clean, and filters definitely work, because water tastes great and I haven't had to descale the kettle for months.
There were a couple of a teething problems at first, but both were quickly identified from the photos I sent to MDC Water. One was due to the plumber incorrectly connecting the filter, the other required changing the order of the filters.
Quality, functional and effective product (that doesn't break the bank), prompt and helpful support, easy ordering, and fast delivery - it's clear to me that MDC Water genuinely cares about the business and its customers. I have and will continue recommending them to others. And easy five stars and a big thank you from me.
Nick - NSW
Absolutely love this tap. Looks and feels fantastic- great quality.
” Due to a stomach issue, it has been necessary for me to drink filtered water for the last 30 years, so filtered water systems are a very important part of my life. Over the years I have had some good and some very bad experiences with water filters. Several years ago I came across MDC Water and now they are the only place I go to whenever I have an issue with water filters. Now, I buy anything to do with water filters, from MDC as their pricing, delivery, knowledge and customer service are the best. Last week, I replaced some quick change filters and accidentally snapped one of the housings. Rather than recommend I buy a whole new system, MDC suggested I can just replace the particular broken housing. 20 minutes after receiving the new housing, the housing is replaced, the replacement cartridges are in, and my family and I are drinking nice clean water again. Thanks so much Osama, for all your help.”
Margaret - NSW
Absolutely fantastic customer service and products!
We love our underbench filtration system but broke one of the heads when trying to replace a cartridge in a very tight spot. Rang the company and received immediate help via phone to fix our problem despite them being on holiday! Couldn't get any better. Needless to say, we will be finding a new spot for the filters (previously installed by a builder).
John - NSW
We would definitely recommend MDC and return for our cartridge replacements when they are due.
Having recently purchased a black filter tap to complement our recent kitchen renovation it was a no brainer that we go back to MDC when our old undersink water filter purchased from another supplier years ago sprung a leak. We purchased a Hyundai triple filter after the pros and cons of the various cartridges combinations was explained, there was no pressure sales involved so it was a pleasant purchase and an easy install. We would definitely recommend MDC and return for our cartridge replacements when they are due.
C - VIC
I am legitimately shocked at how quickly the filter just arrived.
” Ordered it on a Sunday when they likely aren’t even open, got a shipping update on Monday and it was at the door on Wednesday morning. I hadn’t even arranged a plumber because I thought would be at least 2 weeks to arrive like everything else during covid. System looks great. Will update this after installation 😁.”
Nina - VIC
So much easier than refilling a brita filter on a daily basis. Now we have amazing tasting water…. literally on tap.
” Finally bought the tap and filter combo. Best $ I’ve spent in ages. So much easier than refilling a brita filter on a daily basis. Now we have amazing tasting water…. literally on tap. Very fast delivery, easy to install ourselves and the reminder emails when i need to change the filter will be so handy. Thanks MDC!.”
Reg - NSW
Super Fast delivery and so easy to install. Arrived with in 48 hours. Have used MDC for 2 years now
“ Super Fast delivery and so easy to install. Arrived with in 48 hours. Have used MDC for 2 years now after installing one of their 2 in one taps and Hyundai membrane filter system. Never looked back. Chane cartridges every year We love it.”
Alessandro - QLD
Excellent product indeed. I have been waiting for a full 11 months to post my review.
Excellent product indeed. I have been waiting for a full 11 months to post my review.
After researching for years and a little hesitant about the value cost/quality I decided to purchase this 4 stage alkaline system.
The water is the best tasting we have been drinking and there is no comparison even with bottled water for taste. We use it for cooking , for drinks , and the girls now find other waters nasty to drink, so that’s good as we were trying to get them off to drink tap water when not home.
I am purchasing now the replacement cartridges ( thanks to the MDC Water for the reminder) at a fantastic price for the 12 months service ahead and looking forward to more healthy water. thank you
Margaret- QLD
Rang the company and received immediate help via phone to fix our problem despite them being on holiday!
Absolutely fantastic customer service and products! We love our underbench filtration system but broke one of the heads when trying to replace a cartridge in a very tight spot. Rang the company and received immediate help via phone to fix our problem despite them being on holiday! Couldn't get any better. Needless to say, we will be finding a new spot for the filters (previously installed by a builder).
Grant - NSW
Ordered a triple stage filter kit, it arrived so quickly I thought I had stumbled into ‘the butterfly effect’
” Superb, no fuss service with MDC water. Ordered a triple stage filter kit, it arrived so quickly I thought I had stumbled into ‘the butterfly effect’. Very easy to install and over the moon with the results. Cheers.”
Yoorim - NSW
I upgraded from 1 filter to 3 this year, and the special sale prices made it affordable. Wishing prosperity to the business and looking forward to using it for a long time.
I've been using MDC Water for over 2 years. It's not only easy to install, but also incredibly convenient to replace the refill. The delivery is impressively fast. I upgraded from 1 filter to 3 this year, and the special sale prices made it affordable. Wishing prosperity to the business and looking forward to using it for a long time.
Marion - NSW
kept filter system. Refund for tap was in my account within days..
“ A new kitchen will be installed shortly and I ordered online three way mixer tap and under sink filter system. Delivery was quick. I found the mixer tap was too tall for my small kitchen which I should have checked and returned to MDC but kept filter system. Refund for tap was in my account within days..”
Wendy - NSW
Excellent service provided by MDC
“ Excellent service provided by MDC. We have purchased water filters for many years however the service provided by MDC has been the best above all the rest. The system is easy to install and maintain, and any issues are quickly attended to, and help is always available. Well done MDC we will always recommend you and your systems because you follow through.”
Frank - VIC
Excellent service and prompt delivery
Excellent service and prompt delivery, have only just installed and working perfectly with pure clean water, will update the review in 6 moths
Greg - WA
Excellent product working very well.
Excellent product working very well. Filters are very easy to install and replace.
Giles - SA
We are really happy with the system, great water. We have 3 of the units
We are really happy with the system, great water. We have 3 of the units (one we use at Caravan sites), and just ordering another for my son as he moves into his own home. Service is great as well
Mike - QLD
Easy to install for great tasting water
Quick delivery, easy to install for great tasting water, I recommend
Chris - NSW
Fantastic system, easy to install and mount. Carltridges easy to change. Great tasting water
Fantastic system, easy to install and mount. Carltridges easy to change. Great tasting water. Easy company to deal with, friendly and fast service
Susanne - VIC
Purchased in march 2020
Great fast postage tap and filter good quality…water tastes great also a bonus is the fiter replacement reminder service…great idea….purchased in march 2020
Natalie - QLD
We have had this system in for over a month now and it is fantastic. Wish we had purchased it earlier.
We have had this system in for over a month now and it is fantastic. Wish we had purchased it earlier. We also purchased a 3 way mixer. Would definitely recommend.
Milan - NSW
Very quick delivery for Xmas peak arrived undamaged and well packed
Very quick delivery for Xmas peak arrived undamaged and well packed
4 Stage Ultra Filtration Undersink Water Filter System
If you’re looking for undersink water filter systems that deliver fresh, pure water right from your kitchen, the Waco 4 Stage Ultra Filtration is designed to raise your expectations. Forget buying bottled water or worrying about odd tastes, this system brings four layers of under sink water purification to your home, your family, and every recipe you make.
How It Works: Four Layers, Real Results
- Stage 1 – Sediment Pre-Filter: This tough 5-micron filter is your first line of defense, capturing dust, rust, and suspended sediment so your water looks and pours clear every time.
- Stage 2 – Carbon Block: Tackles chlorine, stubborn odors, and organic compounds, removing the off-notes you notice (and the ones you don’t).
- Stage 3 – Ultra Filtration Membrane: With a 0.03 micron hollow fiber design, this stage specializes in bacteria removal—catching E-coli, giardia, viruses, colloids, and more. You get peace of mind with every glass.
- Stage 4 – Final Carbon Polish: The last stage ensures any remaining chlorine, chemical traces, or musty flavours are erased for good. Every cup tastes pure and fresh, whether you’re hydrating or cooking.
Smart, Space-Saving, and Simple
Waco designed this under sink water filter to fit the realities of modern kitchens. The compact, slimline system, it can be installed vertically or horizontally, so it never hogs your storage space or interferes with your bins. The patented color-coded cartridges twist in and out easily, meaning easy installation and no more complicated filter changes.
Tap Compatibility for Every Kitchen
Worried about fit? This system works perfectly with most 3 way taps, all filtered water taps, and of course, every MDC tap. All the fittings you need are in the box, including mini valve, pressure limiting valve, 2m of tubing.
- Note: This filtration system does not include a faucet by default. Please add a faucet or 3-way mixer to complete your setup. If you already have a compatible filter tap, you can skip this option.
Ideal for Renters, Caravans, or Outdoor Setups
Renters and travellers love how this system installs and uninstalls with zero damage, making it the top pick for caravan owners and outdoor kitchens. It goes wherever you do, so your water always stays pure.
Maintenance, Real Talk, and What to Expect
- Major components are NSF certified, but the system as a whole is not.
- Designed for use on biologically safe water supplies (municipal or pre-treated).
- Ultra fine filtration means a slightly slower flow compared to basic filters—but you get higher quality purification in return.
- Flush daily for 10 seconds before first use, 30 seconds after any 3-day gap, and 3–5 minutes after new cartridge install.
- Actual cartridge appearance may vary as we continue to improve the product.
Why Australian Families Trust MDC
With MDC, you get much more than just undersink water filter systems. Every unit comes with a 1-year warranty, 30-day money-back guarantee, and free shipping across Australia. Our team is here when you need us, so you can trust every drop.
Specs at a Glance:
- Filtration: 4-stage (sediment pre-filter, post carbon block, ultra filtration membrane, final carbon block)
- Micron rating: 5 micron (Stage 1), 0.03 micron (Stage 3)
- Size: 35 x 33 x 12 cm
- Cartridge life: 12 months
- Installation: Vertical or horizontal
- Tap compatibility: 3 way taps, filtered water taps, all 1/4" tubing taps
- Component quality: NSF certified materials
- Warranty: 2 year
- 14-day money-back guarantee
- Free shipping Australia-wide
Shipping Information:
We offer free shipping Australia-wide on all orders, excluding rural areas. Rural addresses may incur additional shipping fees, calculated at checkout based on your location.
All orders are carefully packaged and dispatched promptly within 1-2 business days to ensure safe delivery directly to your door.
Returns & Refund Policy:
Your satisfaction is important to us. That's why we offer a straightforward 14-day money-back guarantee. If you're not completely satisfied with your purchase, simply return the item within 14 days of receiving it.
To be eligible for a return:
- The product must be unused and in its original condition.
- The product must be undamaged and returned with all original packaging.
Please contact our customer support team to initiate a return. Once your return is received and inspected, we'll promptly process your refund back to your original payment method.
Discover more in our FAQ
What’s the difference between twin, triple, and four-stage (alkaline) filtration systems?
Our under sink filters vary by how many stages of filtration they use, each designed to meet different household needs. Twin-stage systems come in two versions: the Waco Twin uses a sediment filter followed by a carbon block to remove dirt, rust, chlorine, and chemical contaminants, making it ideal for improving basic water quality and taste. The Twin Ultrafiltration model replaces the sediment filter with a 0.03-micron ultrafiltration membrane, which also removes bacteria and viruses, offering a more advanced level of protection for homes with inconsistent water quality. Triple-stage systems offer more filtration; one version combines sediment, carbon, and ultrafiltration for reliable removal of particles, chlorine, and pathogens, while the alkaline model starts with ultrafiltration, then adds a mineral-rich alkaline filter to boost pH and improve taste, followed by a carbon stage for final polishing. Our four-stage systems offer the most complete filtration in our standard (Not Reverse Osmosis) line up. The standard version runs your water through sediment and carbon filters, an ultrafiltration membrane, and finishes with a second carbon stage to polish the taste. The alkaline model swaps that final carbon stage for an alkaline cartridge that boosts pH and adds healthy minerals like calcium and magnesium, then finishes with carbon to clean up any remaining taste or chemicals. The more stages your system has, the more protection you get from basic chlorine removal in our twin systems, to bacteria and virus filtration in triple models, all the way to smoother, mineral-rich water in our four-stage alkaline setups.
What contaminants do these filters remove, and what don’t they remove?
Under-sink multi-stage filters remove common tap water contaminants: sediment (dirt, sand, rust), chlorine (and the bad taste/odor from it), and organic chemicals like pesticides. The ultra-filtration membrane can also block bacteria, parasites and microplastics, and the carbon stages help reduce some heavy metals (e.g. lead). However, they do not remove dissolved minerals or salts – things like calcium, magnesium, and fluoride are generally not filtered out (which means healthy minerals stay in your drinking water, but fluoride and very fine dissolved solids will also remain).
Does this system remove fluoride from the water?
No, standard under-sink ultra-filtration systems won’t significantly remove fluoride. Fluoride is a dissolved mineral, and our filters are not designed to eliminate it. Typically, only a reverse osmosis system can effectively reduce fluoride in water. So if fluoride removal is a priority (for example, for mixing baby formula or personal preference), you’d need to use an RO system, otherwise, the ultra-filtration system will leave the fluoride in while removing other contaminants.
How is ultra-filtration different from reverse osmosis?
Both are fine filtration methods, but they are different through their filtration methods. Ultra-filtration (UF) uses a membrane with about 0.01 micron pores that blocks sediment, bacteria, etc., but it lets dissolved molecules like minerals & fluoride pass through. Reverse osmosis (RO) uses an even tighter membrane (~0.0001 micron), which removes virtually all impurities *including* dissolved salt, minerals and fluoride. UF systems have no wastewater (all the water goes to your tap) and run on normal mains pressure with no tank. In short, RO gives a higher level of purification (removing things like fluoride and total dissolved solids), while UF provides clean, great-tasting water without the complexity – it retains natural minerals, and no water wasted.
Will installing a filter system reduce my water pressure or flow rate?
The filtered water stream will be , especially with ultra-filtration systems, which naturally have a more restricted flow due to a finer membrane. The actual flow rate can vary and depending on the quality of your inlet water — higher sediment or poor-quality water can slow things down more. That said, our systems still deliver enough flow to fill a glass in a few seconds. If you’re using a separate filter tap, your main kitchen tap pressure won’t be affected. And if you install a 3-way mixer tap, your regular hot and cold water flow stays the same — only the filtered water comes through at a slower rate, which is still fine for drinking and cooking.
How often do I need to replace the filter cartridges, and are they easy to get?
Generally, you should replace the filters about every 10 to 12 months. In most Australian households with municipally treated water, an annual filter change is recommended to keep your water quality high. The replacement cartridges are readily available – you can buy them from us directly. Replacing the cartridges is straightforward: you just shut off the water, twist and pull out the old cartridges, and swap out the old cartridges for new ones. The whole process only takes a few minutes, and no special skills are required.
My filtered water looks cloudy or has tiny black particles right after installation – is something wrong?
No need to worry – this is a common occurrence when a new filter is installed, and it’s only temporary. Cloudy or milky-looking water is usually due to tiny air bubbles trapped in the cartridge, which make the water look hazy; these will dissipate after the initial flush. If you see small black particles, those are just harmless carbon dust from the new carbon filter cartridge. To fix both issues, simply flush the system by running the filtered water tap for a few minutes (around 5 minutes is usually enough). This will purge the air and rinse out any carbon fines, and your water will then be clear, clean, and ready to drink.
Does it come with its own faucet, and will I need to drill a hole in my sink?
Yes, our under-sink filter systems can include a dedicated filtered water tap (a sleek, stainless steel tap) that you install on your sink or countertop. Most modern sinks already have a spare hole (used for a soap dispenser or spray hose) that can be repurposed for the filter tap; if not, you’ll need to drill a small hole (around 12mm) for installation. If you’d rather not add a separate tap, you can choose a 3-way kitchen mixer tap that combines your regular hot and cold water with filtered water in a single fixture. A 3-way tap replaces your existing kitchen tap and uses separate internal channels, so you get filtered water on demand without drilling an extra hole. If you already have a filtered water tap or 3-way mixer installed, you can also purchase the filter system on its own — it uses a standard 1/4" connection that fits most setups.
Can I install the system myself, or do I need a plumber to do it?
Our under-sink systems are designed with DIY installation in mind – many homeowners in Australia install them successfully on their own. The package comes with everything you need (tubing, fittings, and instructions) to tap into your cold water line and connect the filter and faucet. No electrical work is required, and the plumbing connection is similar to installing a dishwasher or kitchen tap. If you’re not comfortable doing it yourself, you can hire a professional plumber or handyman. In practice, a lot of people choose the DIY route or use a handyman – just be sure to follow the instructions and shut off your water supply during install.