WISY's 4-stage cleansing principle ensures that rainwater is clean enough to store. Users of WISY's rainwater harvesting system are not completely dependent on public water utilities and have access to their own clean water supply during dry spells.
Rainwater filtered by the vortex fine filter or another WISY pre-tank-filter and the downpipe filter is not only clean, but also highly oxygen-rich. This is important because the growth of anaerobic bacteria is inhibited in oxygenated water.
The calming inlet carefully distributes fresh water in the storage tank without resuspending sediments. The water in the storage tank stays clean.
The top surface layer of the water is regularly flushed into the multisiphon overflow, thereby preventing the formation of a surface barrier layer and ensuring an optimum exchange of oxygen between air and water. The storage tank overflow is also protected by the backflow prevention device, the vermin guard and the odour seal.
Clear rainwater is extracted from the cleanest part of the tank, i.e. from around 20 cm beneath the water surface. The water is sucked in through the floating suction filter.