A Sustainable Health Spa: Embracing the Water and Energy Saving Benefits of Regenerative Filtration

Evoqua's Defender RMF enhances water quality and efficiency at leading German spa


Located on the shores of the Stettin Lagoon in Ueckermünde, Germany, Haffhus Hotel & Spa provides an eco-conscious destination for travelers to relax in and enjoy its idyllic surroundings. Haffhus is committed to being carbon neutral and completely energy self-sufficient via the generation of renewable energy onsite.

To ensure it continues to deliver the very best visitor experience, a substantial renovation of the spa area began in 2018. This included the addition of several new saunas, a children’s pool, a whirlpool, and a 7 x 18m outdoor pool.  These new facilities required a reliable supply of high quality water that would keep bathers safe and comfortable, using a technology solution that was cost and operationally efficient, had a low footprint and worked within the limits of the site’s off-grid energy system.


Pool builder Schwimmbadtechnik Lange GmbH recommended the Evoqua Defender® Regenerative Media Filter for the Haffhus spa project. The expert pool builder had successfully installed a Defender filter on a previous project and knew the benefits of the technology. The Defender was chosen for this installation as it was proven to deliver consistent and reliable high water quality, while minimising the energy required for filtration.

The model selected was the Assero SP-29-36-500 with Flexosol® 3000 plastic coating and flexible capillaries made of T316L stainless steel helices. This model was chosen as it would deliver effective solids removal for the predicted flow for Haffhus and its compact design allowed for easy installation into the site’s existing facilities and infrastructure. The 84cm diameter filter is easily transported to its destination, without the requirement for structural changes. For comparison, when using traditional sand filtration, two filters with a diameter of 150 cm would have been necessary.


The installation of the Defender filter for Haffhus Hotel & Spa was a success and is delivering against all project objectives. As well as exceptional water quality and a reduced footprint, Haffhus is realising significant water and energy savings, which are critical to ensuring it can operate as carbon neutral.

When compared to traditional sand filters, the Defender filter is eliminating the need for backwash cycles, saving approximately 90% on water consumption. With two conventional sand filters, according to DIN 19643, about 13 m³ of wastewater per backwash would be generated over the usual 5 minutes. In contrast, the used Defender® Filter only produces 1.4 m³ of wastewater per backwash. This corresponds to a 90 percent reduction in wastewater production. Furthermore, energy is saved that would otherwise have entered the sewer system along with the wastewater.Reducing the consumption of water yields savings in electricity, since all incoming make-up water needs to be heated to a comfortable 30°C for use in the pools. In addition, further energy savings are realised thanks to the Defender filter’s innovative design, as it requires significantly less pressure to pass water through the media, which directly results in energy savings from pumping. Overall, the Defender® filter provides approximately 30% in electricity savings when compared to alternative filtration options.

Haffhus has also been able to minimise its use of chemicals, as the high performance Defender filter removes particles down to 1 micron without the use of flocculant chemicals. This saves on costs and reduces the need for chemical storage and handling.

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