Sabine Stuiver

Sabine Stuiver did not set out to build a water company. She and her husband, Arthur Valkieser, were retired serial entrepreneurs who had run businesses in completely different markets, and they had reached the point in life where, as she puts it, you start to realise how lucky you have been and decide you want to give something back. Water was Arthur's long-standing interest, and the two of them turned an overlooked idea, recycling the water a home has already used, into Hydraloop, which they co-founded in 2015. It is, in her own words, "a husband and a wife and a garage story."

Hydraloop makes a compact appliance that sits in a house like a fridge or a washing machine and quietly recycles greywater, the lightly used water from showers, baths and washing machines. Instead of filters or chemicals, it cleans that water through a sequence of physical and biological steps and finishes with UV disinfection, then returns it for toilet flushing, laundry, the garden or a pool. The result is a home that uses up to 45% less mains water. For bigger buildings, the modular Hydraloop Cascade ganged several units together in the basement of a hotel, a sports club or student housing, so the same idea scales from a single house to a whole development.

Sabine Stuiver's real talent, the one that separates Hydraloop from the many water technologies nobody has heard of, is making the invisible legible. She argues that most water tech fails commercially because it is too hard to explain, and her counter-move was to make Hydraloop something an ordinary buyer instantly understands. That paid off spectacularly in January 2020, when Hydraloop went to CES, the giant Las Vegas electronics show, with two 45-kilogram demo units as luggage, and walked away with Best of the Best, the single best product across more than 20,000 entries, ahead of Samsung, Sony and BMW, along with prizes for best startup and best sustainable product. TIME and Newsweek both put it on their best-of-CES lists, and the Netflix documentary Brave Blue World, which features Sabine, has been generating inbound interest every week since.

Sabine Stuiver is candid that a viral moment is not a business. The world shut down weeks after CES, conventional investors retreated, and the first real money came from the founders' own network plus a matching bank loan rather than a tidy venture round. The company kept manufacturing asset-light, designing the product in-house and outsourcing the build to a partner factory so it could grow without sinking capital into a plant of its own. By 2024 Hydraloop had roughly 130 partners worldwide and, as of 2026, has raised about $15.6 million, including an $11.4 million Series B led by the Dutch state investor Invest-NL. Sabine, who led marketing for over nine years, now serves as the company's corporate ambassador, carrying its case to stages from the UN's water week to COP28.

What makes Sabine Stuiver worth listening to is the conviction underneath the showmanship. She frames water's real problem as a pricing one, that it is precious almost everywhere but cheap almost everywhere, so people never see the cost of wasting it, while two billion people who lack it know its value exactly. Her north star follows from that:

“Within 10, 15 years' time, every new house, every new building will have to have a water recycler in it, standard, demanded by building regulations. Water recyclers become a standard item in every building, like air conditioning.”

Sabine Stuiver is, in the end, a marketer who found a mission: the rare water-tech founder who can make a recycled-water appliance feel inevitable, which is most of why a small Dutch company is on television sets and in buildings far beyond the Netherlands.