New Delhi: Twenty-two-year-old Vishal was in the final year of his bachelor’s at IIT Jammu when he came across an Instagram post about two researchers building a water-filtration start-up. Fascinated, he emailed them, asking if he could be a part of the team.
Today, two years later, Vishal is the youngest member in a team of researchers, led by MIT professor Rohit Karnik, building DetoXyFi, a water tap filter which sells at Rs 899 in the Indian market.
Early in August, Vishal and the team represented DetoXyFi at the EAW Global Aqua Expo 2026 in New Delhi, and highlighted that their product, born out of research at the Massachusetts Institute of Technology, can now remove 99.9 per cent of bacteria from water, does not use any electricity, and does not waste any water, unlike existing RO purifiers.
“Our aim in the long run is to replace RO purifiers from Indian houses and replace it with our product — the Jal Kavach. RO purifiers consume a lot of electricity, they have a high maintenance cost, and for every litre they waste three litres, which is unacceptable. Our team shares the same goal — to build a product that is affordable for all,” Vishal told ThePrint.
A dream built out of childhood memories
The co-founder of DetoXyFi, Dhananjay Goel, is an IIT Delhi graduate. Growing up in the hills of Himachal Pradesh, Goel’s family had a motto when it came to water — two bottles to drink, and one bucket to bathe. He carried the memory of that struggle and chose to build DetoXyFi as a way to deliver clean water to every household.
Vishal, too, had faced a similar struggle. He recalled his early childhood in Amritsar where tap water had to be boiled and stored in copper containers before it was safe to drink. Even before he joined DetoXyFi, Vishal had begun working on water purification projects independently during college.
One of his projects was a small copper-plated bowl that could be placed into a water bottle. The copper ions would then interact with the water and kill off bacteria.
When Goel interviewed Vishal, he asked him why a young graduate deserved a spot in an upcoming start-up with a team of PhD students and an MIT professor.
“I said that a PhD student is trained to follow procedures and SOPs. But I just have a bachelors, I am creative and I have the mind to try out different things, rather than follow a straight or standard path,” Vishal said.
That mindset to be able to pivot from one design to another, one technology to another, has been essential, especially since the team’s product today is very different from what it once was.
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From MIT to Indian taps
The research behind DetoXyFi, published in March 2021 in Nature Communications, was about using xylem to purify water. Xylem is the tissue inside trees that transports water from roots to leaves.
Vishal explained that a tree sucks up water from the ground and filters it automatically. At MIT, professor Karnik, a mechanical engineer studying nanofiltration and nanofluids, had tried to use that natural filtration membrane.
Jal Kavach is not built on the same technology. Vishal said that xylem turned out to be very difficult to commercialise because of its short shelf-life. The filter lasted only seven days, and there was no chemical way of preserving it without introducing chemical substances into drinking water.
Today, Jal Kavach uses a filter made of a composite membrane including activated charcoal. The steel mesh and other material remove larger particles such as sand, rust, and debris from aging pipes, while the activated carbon reduces chlorine, removes unpleasant taste and smell, and absorbs organic compounds.
The membrane has pores smaller than bacteria, and as they clog, the water flow decreases, telling the user that the filter needs to be changed.
“How long the filter lasts, depends on how dirty your water is. We can’t say it has a universal one-year life span. But it can filter about 7,500 litres. This can mean that the filter lasts anywhere from four to five months to even more than a year,” said Vishal.
The team first put their product up for sale in June 2025 through Amazon, Blinkit, Flipkart, JioMart, and other platforms. They made only Rs 5 lakh in 2025, but have already made Rs 20 lakh this year, in revenue.
Vishal said these early sales were about testing the product and gaining feedback. Today, they are already upgrading the product. But the biggest challenge ahead remains the stubborn Indian consumer.
“In India, we face a major problem. People are not quickly adaptable. They are so used to the RO filter that they don’t trust any other method as a filtration device. So initially, people did not trust our product, but slowly as we put out small ads we have seen better reception,” said Vishal.
Even as DetoXyFi tries to reinvent itself and make its way into the Indian markets, the start-up is hardly ‘brand new’ anymore. Its earlier versions were tested in Uganda, Madagascar, and Kenya. At the time, the technology had won several competitions such as the Jacobson Social Impact Prize by the University of Pennsylvania.
For Vishal, the challenge remains to keep upgrading the technology and the product and to simultaneously convince Indians that Jal Kavach will make sure their water is safe and potable.
(Edited by Aamaan Alam Khan)