Maelstrom™ Rainwater Filter

10.00 LBS
Calculated at Checkout
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Product Overview


A breakthrough in rain harvesting technology.

Raising rainwater to entirely new levels.

Maelstrom, the most advanced filter we have ever made, sets a new standard in pre-tank rainwater filtering.


1.       A single point, tank-top filter with a ground breaking U-shaped design.

2.       Multiple Barriers (2mm and 180 micron) filters particles 5 times smaller than is achieved with a standard tank screen.

3.       Reduces the hassle of cleaning leaf and debris build-up through Self-flushing.

4.       Blocks out light, replacing tank screen and solar shield.

5.       Is a versatile product, able to be installed in a variety of pre-tank locations.

6.       Reduces frequency and cost of tank cleaning by lowering common sediment build up through cleaner tank water.



1.       Rainwater enters the Maelstrom through either of the horizontal-facing couplings.

2.       The rainwater then enters the Primary Filter. The unique curved filter slows the velocity of the water by changing the direction of its flow.

3.       Surrounding the Primary Filter is a Secondary Filter, comprised of a nylon mesh bag which filters fine particulates larger than 180 micron. This filter assembly is easily removable and will require periodic maintenance.

4.       The filtered rainwater then continues to move through the Maelstrom to the Filtered Water Outlet and into the rainwater tank or pipe (if attached).



According to the manufacturer, the Maelstrom can retain 96% of water at flow rates up to 9,510 gallons per hour, and depending on roof area and rainfall intensity, the flow rate which would enter the Maelstrom in the system could vary.

Some examples of rainfall intensities and roof areas which the Maelstrom can manage are:

- On a 2,000 sq.ft collection area, if the rainfall intensity is 7 inches/hr, and all is connected to the Maelstrom, it would be expected that there is 8,727 gallons PER hour flowing through the Maelstrom.  The Maelstrom will perform well in this scenario, capturing around 96% of the water.  This is considered a severe rainfall event.

- On a 5,000 sq. ft collection area, if the rainfall intensity is 2.5 inches/hr, and all is connected to Maelstrom, it would be expected that 7,792 gallons would flow through the Maelstrom, of which 96% or more would be captured. This is considered still a heavy rainfall event.

All the above is measured with clean water. With debris, the results vary with different types of leaves and debris which might be found in different geographical locations.


Maelstrom’s ultra-fine 180 micron filter removes particles 5 times smaller than standard rain-head and tank screens.


Even at rapid flow rates of 9,510 Gallons per Hour (158 GPM), Maelstrom retains 96% water catchment efficiency.


Filtering multiple lines at a single point is a simple way to keep tanks filled to the max.

How it works.

Rainwater from the gutters flows into the U-shaped filter.

Step 1

The first 2mm (0.08") filter (A) diverts leaves and larger debris and the second, ultra-fine 180micron filter (B) stops even finer particles.

Step 2

During major rain events, overflow helps flush-out leaves and debris.

Step 3

A final 0.955mm (0.04") screen prevents mosquitoes entering tanks to breed.

Step 4

The filtered water is funnelled through the base into the tank.

Installation Types

-Tank Top
-In Tank
-Wall Mounted
-Stormwater Pit

Suitable for just about anywhere.

-Residential properties
-Remote areas & farmsteads
-Commercial & local retail
-Schools & universities
-Sustainable living & green buildings
-Transportation hubs

It tackles the big issues.

Filtering multiple lines at a single point is a simple way to keep tanks filled to the max.

  • Having enough water.
  • Filtering leaves and debris.
  • Removing suspended particles.
  • Securing the tank to keep out pests (including mosquitoes) and sunlight (to prevent algae growth).
  • Easy maintenance.

Easy install on systems new & old.

Filtering multiple lines at a single point is a simple way to keep tanks filled to the max.

  • Tank Top
  • In-Tank
  • In-Ground
  • Wall Mounted

Insist on a clear, colorless, odorless and plentiful rain water supply.

Maelstrom Brochure
Installation Instructions


Primary Filter
2mm (0.08") Aperture, Polypropylene

Secondary Filter

0.18mm (180μm) Aperture, Nylon

Mosquito Proof Screen

0.955mm (0.04") Aperture, SS316

Inlet & Outlet Pipe Size

DN100 (110mm OD) / 4" OD


Flexible, EPDM

Body & Base Plate

ABS, Polypropylene

Performance Data:

Water Catchment Efficiency @ 5L (1.32gal) / second*


Water Catchment Efficiency @ 10L (2.64gal) / second*


*For wet/charged system configuration with clean water flow