The Dutch water-recycling company teaching homes and buildings to use their water twice.
THE APPLIANCE THAT CLOSES THE LOOP. The slim, refrigerator-sized Hydraloop H300 collects greywater from showers, baths and washing machines and returns it clean - no chemicals, no filters. Photo: Hydraloop.
Most water in a home is used once and sent down the drain. Hydraloop, founded in 2015 in the Netherlands by Arthur Valkieser and Sabine Stuiver, argues that this is a design flaw worth fixing - and that the fix belongs inside the house, not at a distant treatment plant.
The company builds compact, certified water-recycling systems that collect the greywater from showers, baths, washing machines and even the condensation from tumble dryers and air-conditioning units. Inside a cabinet roughly the size of a slim refrigerator, that water passes through six treatment steps and comes out clean, clear and safe enough to reuse for toilet flushing, laundry, garden irrigation and topping up a swimming pool. A single unit can recycle up to 85% of a household's water and cut both fresh-water consumption and sewage output by as much as 45%.
What sets the approach apart is what it leaves out. There are no chemicals to add and no filters to replace - the treatment relies on physical and biological processes including sedimentation, flotation, an aerobic bioreactor and UV disinfection. An IoT app lets the household set reuse priorities, watch the recycling process and track how many litres it has saved. The result is water recycling that asks nothing of the person using it: same shower, same comfort, roughly half the footprint.
Cities face drought, rising water bills and strained sewage systems. Building new supply is slow and expensive. Hydraloop's bet is decentralization: treat the water where it is used, at the scale of a single home or building.
The company positions its product as an appliance rather than an engineering project, which is the point. Traditional greywater setups are plumbed installations that demand maintenance and expertise. Hydraloop packages the same idea into a plug-and-play cabinet that a homeowner, a developer or a hotelier can adopt without becoming a water engineer.
For developers, water resilience has become a selling point; for hotels and resorts, recycled water supports green certification and lower running costs; for off-grid and water-scarce sites, on-site reuse can be the difference between viable and not.
Figures cited by Hydraloop for its residential systems. Actual savings vary by household and configuration.
The compact home system: 300-litre capacity, roughly 0.8 sqm footprint, treating around 360 litres a day. Recycles up to 95% of shower and bath water.
A 600-litre unit for bigger homes and small commercial buildings, using the same six-stage, chemical-free treatment process.
A modular system that links multiple units for hotels, apartment blocks and high-demand commercial buildings - scalable water reuse.
The IoT companion lets users set reuse priorities, monitor the recycling process in real time and see exactly how much water they have saved.
Six physical and biological steps - sedimentation, flotation, dissolved-air flotation, foam fractionation, an aerobic bioreactor and UV disinfection - with no chemicals or filters.
Appliance sales to homeowners, developers, builders and the hospitality sector through a global distributor and installer network - across B2C, D2C and B2B.
In March 2024, Hydraloop closed a Series B round of €13.5 million, anchored by a €10.5 million investment. Impact investors Invest-NL and NV NOM joined proptech investor AMAVI Capital to fund research, sales engineering and global expansion. Total funding raised to date is roughly €22 million-plus.
€10.5M investment led by:
Co-founded Hydraloop in 2015 and leads the company as chief executive, steering its move from a Dutch startup to an internationally distributed water-tech brand.
Co-founder and chief marketing officer, a recognizable voice for the company as it built awareness through CES, media and documentary features.
Hydraloop sits at the intersection of cleantech hardware, smart-home consumer tech and the built environment. Its competitors range from other greywater-system makers - names like Greyter, Aquacell and Nexus/RewaterLife - to conventional rainwater harvesting and mains-only plumbing. Its differentiator is the packaging: certified, chemical-free, filter-free and consumer-friendly, sold as an appliance rather than an installation.
The company reaches customers through regional partners, including Hydraloop USA and an Australian presence represented by Sydney-based circular-economy leader Lisa McLean. In 2022 it partnered with Sydney Water on conservation initiatives - a signal of how national utilities view decentralized reuse as part of the water-security toolkit.
Arthur Valkieser and Sabine Stuiver start the company in the Netherlands to build decentralized water recycling systems.
The company launches its first commercial water recycling unit.
Hydraloop sweeps top honours at CES 2020 in Las Vegas and appears in Netflix's Brave Blue World.
Receives a UN WIPO Global Award and partners with Sydney Water on conservation initiatives.
Raises a Series B round led by Invest-NL, NV NOM and AMAVI Capital to scale globally.
Sources: Hydraloop.com · Wikipedia · Crunchbase · Dealroom · Impact Investor · Innovation Origins · Silicon Canals · Electrek · Dutch Water Sector · Informed Infrastructure. Figures are as reported by the company and public press; savings vary by installation.