Reliable Pre-Filter Solutions for Commercial & Industrial Rainwater Systems
Discover high-performance commercial rainwater pre-filters designed to improve water quality, reduce maintenance costs, and support sustainable water management.
Benefits of Pre-Filtration
What if your rainwater tank could stay clean with almost no effort? Prefiltration screens out leaves, pollen, and organic debris while aerating the water before it reaches storage. These two steps starve out the conditions that degrade water quality over time. Decomposing organic matter and oxygen-depleted water are what bacteria need to thrive. Remove both and your tank stays cleaner with less effort.
This is the principle behind the WISY 4-step process. Rather than treating water problems after they develop, prefiltration prevents them from taking hold in the first place. The result is a system that performs reliably year after year with minimal maintenance.
Variables to Consider When Selecting a Pre-Filter
Roof Size
Know your square footage. Larger collection surfaces generate higher volumes of runoff, and your filter needs to handle the flow without backing up or bypassing. For roofs that exceed a single filter’s capacity, multiple units can be combined to manage the full volume.
Rainfall Intensity and Frequency
Areas with heavy downpours require filters that can process large volumes quickly. Regions with frequent light rain may prioritize fine filtration over high flow capacity.
Flow Rate
Match your filter’s rated capacity to your system’s maximum expected flow. Undersizing leads to overflow and lost water.
Debris Load
Properties with lots of trees or areas with high pollen counts need filters designed for greater debris handling. Consider seasonal variations too.
Pipe Diameter
Your filter must be compatible with your existing or planned pipe sizing. Mismatched connections create bottlenecks and installation headaches.
Local Standards and Regulations
Some jurisdictions have specific requirements for rainwater harvesting equipment. Verify compliance before purchasing.
Maintenance Access
A filter only works if it’s maintained. Install yours in a location that allows easy, regular access for inspection and servicing.
How WISY Pre-Filters Work
Watch these short videos to understand how the vortex filter works
Most filters trap debris until you clean them out. WISY filters flush it out as rainfall occurs. Water spins into the filter, swirls around a stainless steel mesh, and separates from debris and particles. Clean water exits to storage. Debris exits to the drain. Leaves, pollen, and sediment are pushed out by the same water that brought it in. That’s why WISY filters stay cleaner, require less maintenance, and are ready for the next rainfall.
Cleaning Your WISY Filter
WISY filters are built for easy maintenance. The stainless steel insert lifts out in seconds. Spray it with a hose, scrub it with a brush, or toss it in the dishwasher. For stubborn deposits, a high pressure cleaner can be used from a distance of at least 20″ to avoid damage to the filter mesh.
Cleaning intervals depend on your location and debris load. A building surrounded by trees will need more frequent attention than one in an open area, but generally every six months is sufficient.
Refer to your product manual for detailed cleaning instructions.
Installation Options
WISY vortex filters can be installed above or below ground, indoors or outdoors, and mounted in a variety of ways to fit your space. When roof square footage exceeds the capacity of a single filter, multiple units can be combined to handle higher flow rates.
Not sure which filter or setup is right for your project? Talk to us. We can help you figure out everything you need for proper selection and installation.
Above Ground
Below Ground
What Are My Options
WFF 100
The WISY WFF 100 is built for smaller projects. It handles roofs up to 2,100 ft2, making it ideal for small offices, retail shops, residential homes, and standalone structures. Compact, reliable, and easy to maintain. When you need more capacity, combine units or upgrade to the WFF 150. Engineered in Germany and built to perform.
WFF 150
Ideal for larger homes, duplexes, and light commercial buildings. The WISY WFF 150 handles roofs up to 5,500 ft2. If your roof exceeds that, you have options: combine multiple units for flexibility, or upgrade to the WFF 300 which handles up to 32,000 ft2. The right choice depends on factors like your layout, local rainfall patterns, and available space. Multiple smaller units often offer more flexibility. German-engineered for long-term performance.
WFF 300
Engineered for large-scale rainwater collection. The WFF 300 handles up to 32,290 square feet per unit. Pair two together and you’ve doubled your capacity. Pair five and you’re filtering over 160,000 square feet. No matter how many units you add, performance holds.
Built for commercial, industrial, and institutional systems. School campuses, municipal buildings, healthcare facilities, this is the filter built to handle it. Installation is flexible, and a shorter version is available for decreased invert or tighter installations.
WFF 300 Stainless Steel Option Available
The WISY WFF 300 VA is built to keep running. Stainless steel construction and a self-cleaning filter mesh mean fewer interruptions and less hands-on maintenance. The two-part housing rotates in 15° steps to fit your space, and the pressure-rated cover opens with one hand. Need to handle abrasive materials? Add titanium nitride coating. Working with food-grade requirements? A higher-grade stainless steel option is available. Also available in WFF 150 and WFF 100.
RMS High Volume (HV) Filter
For projects that demand high-volume filtration, RMS offers the HV filter. Designed and assembled by RMS, it handles roof areas up to 200,000 square feet. Distribution centers, data centers, manufacturing facilities, this is filtration built to scale. Sizes range from 6″ to 24″ with options for outlet configuration, fitting type, sediment removal, and spray nozzles for easy cleaning. Projects at this scale need the right filter. Let’s build yours.
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