Clean Rainwater

The concept of collecting and using rainwater is hardly new; it certainly dates back to Roman times and probably before. What has changed now, as with most other aspects of life, is the technology available to implement it.

In particular this relates to filtration, which we believe to be the most important part of any good system; if the water is cleaned as much as possible prior to being stored, then it is least likely to lead to any problems.

Water that is unfiltered can deteriorate, particularly if there is significant organic matter present as this will ‘strip out’ the oxygen from the water. As a result the water can become stagnant, discoloured or malodorous.

Where water is required for use within toilet cisterns, washing machines or industrial processes it needs to be as clean as possible and not be unpleasant to use. Careful design is therefore very important.

Our rainwater harvesting systems are designed around a four-stage cleaning process developed by WISY AG in Germany that provides clean, oxygen-rich water, free of any particles.

  • Stage 1: Filtration
  • Stage 2: Sedimentation
  • Stage 3: Floating extraction
  • Stage 4: Surface skimming

These four processes are achieved using purpose-designed products.

Stage 1: Filtration

Thanks to the Self-cleaning fine filtration of the WISY® Vortex grin filter, filtered water is in clean, and highly-oxygenated. This is an important factor in inhibiting the growth of anaerobic bacteria.

Stage 2: Sedimentation

The WISY® calmed inlet allows water to enter at the base of the tank with minimum turbulence, whilst adding oxygen. Very fine sediments then quickly settle to the bottom of the tank.

Stage 3: Floating extraction

WISY® floating suction filter. The ball float enables the water to be extracted from the cleanest part of the tank; just below the surface, whilst avoiding any floating particles.

Stage 4: Surface skimming

The top surface layer of the water is regularly flushed into the unique WISY® multi-functional overflow unit, this prevents a surface barrier layer from forming enabling oxygen exchange between the water and air. The overflow unit features an odour seal, and backflow protection proving total tank protection for full BS 8515 compliance.