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Forget putting charcoal on your teeth – Refil says you should be putting it in your water

According to the New Zealand Beverage Council (NZBC), Kiwis are big fans of staying hydrated.

Bottled water purchases have grown more than 25 percent for the past two years, while tap water is also the most consumed drink in New Zealand, NZBC reports, with Kiwis drinking 233 litres of tap water each year on average.

Overall, water represents 29 percent of all drinks consumed, while New Zealanders’ uptake of water has grown 32 percent over the past 10 years.

But Wellingtonian and the creator of Refil, Johnny Huynen, was sick of the metallic aftertaste of tap water and dissatisfied with the filtering options available on the market.

He decided to create a solution, and spent a year researching and tinkering with the design prototypes for a filter before arriving at the final concept, which is available for pre-order on Kickstarter.

The filter he’s created is activated charcoal and is made from coconut shells, which absorb toxins and the positively charged elements found in tap water: copper, lead and chlorine.

Research conducted by Refil at the main five supermarkets in New Zealand has found the filter slots on to 65 percent of bottles you can buy off the shelf. The filter can be used 150 times in a bottle before being recycled, while the charcoal stick is 100 percent biodegradable.

The goal of Refil is to reduce the amount of people buying bottled water, Huynen says, and therefore reduce the amount of waste ending up in landfills.

Its Kickstarter campaign is aiming to raise $50,000 to cover the cost of production. So far, almost $4000 has been pledged, with 38 days to go.

Check out our Q&A on the design of the filter with Huynen below.

Idealog: What inspired you to create Refil?

I’ve always found I got a bleachy and metallic after taste after drinking tap water here in Wellington and it basically meant I’d be buying bottled water out and about, or waiting to go to the gym to use their filtering water cooler. 

I hated the fact I was buying bottled water whenever I didn’t have access to a water filter or a water cooler, and I’d been using reusable filtering bottles as an alternative, but they often ended up leaking, getting tacky and damaged and were always a pain to use. I figured my favourite and most convenient bottles to use were the Pump bottles I’d purchased already, and I always had some lying around at my disposal. I researched activated charcoal and the filtering qualities it has and wanted to create a solution where I could utilise these bottles I’d had already purchased and create a solution to my bottled water buying habits, and my dislike of tap water.

I knew I wasn’t in a position to completely stop buying bottled water – it’s too convenient and tastes 1000 times better than tap water, so I had to come up with something that could at least reduce my consumption of, but be just as convenient as bottled water. And so, the Refil Filter came to life. 

Have you tried your hand at any business ventures before this, or is this your first?

I registered my first business in January 2017 called JUCE Media (Juce.NZ). I’m a videographer, photographer and graphic designer, and did my degree at Massey, so JUCE was a name and a label I could put to the work I was producing. I’d completed work for a couple of local businesses: Baseline print studio, Fitwear, Speedway New Zealand, and Wellington Civil Defence to name a few. It was nice to be able to utilise these skills and put it into something tangible like a new invention.

What was the design process like? How long did it take, and what were the challenges encountered?

Essentially it started off as a few provisional designs, drawings and sketches, and I had completed a few rough 3D models on Cinema 4D. I used the skills I learnt doing my VisCom degree to create a visual representation and a business plan, logos and website mock ups. I’m not much of a 3D designer, but managed to wing it, creating a visual representation on Cinema 4D of the filter and casing using YouTube tutorials.

I figured everyone works best if they can visually see an idea, so if I can make an example to present to people, it’d give me the best head start to answering the questions on whether this design is possible. I took my provisional designs to Exactus Industrial Designers and Engineers in Lower Hutt, and together we worked on creating a perfect casing that would slot into the common sipper cap.


This process took around a year, which was a mixture of building up the capital to invest in their time and changes that were required such as lengths and widths, doing 3D prints and making sure the fit was snug and didn’t fall out with knocks of the bottle. We liaised with Uniplas in Lower Hutt around the tool making for the casing design, which all in all, was quite a smooth process and confirmed we can manufacture the casings locally. 

I’d had measured up my Charcoal filter measurements in accordance with the length, width and circumference of the casing and had the tool made for that in China. 

The first lot of filters we did hardly removed any chlorine and you could still taste it when drinking. With the second batch, we knew we had a working product. A combination of language barriers and overseas liaising was a process in itself.

We got our first prototype tested in Lower Hutt at Eurofins Laboratories, and it proved to remove 50 percent of total chlorine and 40 percent of copper and lead. We’re hoping if our Kickstarter is successful, we’ll have the capital to be able to get those percentages even higher with a slight tweak in the measurements on the filter.

I’d presented my provisional designs and business plan to a few innovation grants and got turned down from them all, so I figured my problem here is I don’t have something tangible. If I can just get this made and in my hands and people’s hands, it’d be easier to get people on my level when selling this idea. The most important thing for me of this whole process was to just get it made, get a prototype done and you’re away swinging.

Was it hard was it to design a filter that fits into so many different bottles?

I’d always been weirdly fascinated by the fact I could screw a Pump sipper cap onto an h2go or Coke bottle for whatever reason. As a kid, I remember having water fights with some 2.25 litre Coke bottles with a pump sipper cap on it, and it worked perfectly, so this prompted my thinking that I could find a generic cap (which is a 28mm) that fits on all of these bottles.

I’d essentially designed the filter and casing around the fact it could slip into the inner walls of a sipper cap. It didn’t take long to quickly work out this sipper cap is almost an industry standard with beverages, hence our claim that it fits to 1000s of bottles. I visited the five main super markets here in New Zealand and surveyed all the bottles it would fit, and it worked out to be around 65 percent of the bottles you can buy off the shelf. I ended up spending $200 at Countdown buying all the bottles it could fit to test it.

Elly is Idealog's editor and resident dog enthusiast. She enjoys travelling, tea, good books, and writing about exciting ideas and cool entrepreneurs.

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