4 Step Rainwater Harvesting Systems

construction-370588_640RainBank Rainwater Systems is proud to announce that, beginning June 1st, we will be a dealer of WISY Products and the 4 step system.  A rainwater system designed with WISY products requires minimal maintenance and never needs replacing.


Before entering the tank for storage, rainwater should be both filtered and aerated.  Filtration removes large particulate matter, which frequently both carries and feeds bacteria.  Removal of this particulate matter, along with oxygenation of the water, greatly reduces the amount of harmful bacteria in the tank.  WISY pre-tank filters accomplish both of these tasks, protecting the water quality in the tank.


While filtration removes most of the sediment and bacteria before rainwater enters the tank, a small quantity will settle at the bottom of the tank.  This biofilm layer is beneficial for the tank and may remove additional bacteria and metals from the water.  The WISY smoothing inlet calms rainwater as it enters the storage tank to prevent the agitation of sediment at the rainwater inlet.  The smoothing inlet also helps aerate harvested rainwater by directing water upward and outward, avoiding disruption of the beneficial biofilm layer and preserving water quality in the tank.


Since all harvested rainwater is filtered before entering the tank, the floating filter should never clog but will instead take water from just below the surface.  Water at this depth is of the highest quality in the tank, because any particulate that enters the tank either floats on the surface or settles to the bottom.  In RainBank designed systems, the floating filter acts more as an uptake point for the pump than a filter; thus, the floating filter should never require maintenance.

The floating filter consists of a polyethylene ball and stainless steel filter and is supplied with a standard 7 foot length of food-grade suction hose.  The nozzle connections are available in 1 1/4″ and 2″ sizes.


To prevent backup in the system during heavy rains, the storage tank should always include an overflow protection device.  The WISY overflow device has a flapper valve, which allows water to overflow but protects water quality in the cistern with backflow prevention and vermin protection.  The overflow device also contains an angled opening to provide skimming of small buoyant debris, such as pollen, on the water surface.

Be sure to visit us again as we roll out our products and services associated to the 4 Step System. If you have questions, leave them in the comments section below, or contact us.

Ken Blair
A rainwater collection systems designer and consultant, Ken has designed and installed residential and commercial systems, primarily in the northwest United States for more than 10 years and, in 2014, began consulting and managing builds in other states. Ken is an accredited ARCSA Professional Designer / Installer and Life Member, the Northwest Regional ARCSA representative and advisor to its education committee and is available to speak about Rainwater Collection Systems design and builds.

Ken is a United States Navy veteran, having served on active duty during the Vietnam War era.

A career entrepreneur, Ken created a new business focus with a commercial dive company in Hawaii in the mid 1980′s to respond to and clean up oil spills, oil spill equipment training, service and maintenance for the oil co-op service industry. Ken is passionate about having a positive impact on the environment and is also a founding director of BANK-ON-RAIN (2011-2014), whose mission is to create grassroots solutions for rainwater collection for consumption and agriculture in developing areas of the planet.