Maelstrom Filter

1. Rainwater enters the Maelstrom through either of the horizontal-facing couplings.
2. The rainwater then enters the Primary Filter (J). The unique curved filter slows the velocity of the water by changing the direction of it’s flow.
3. Surrounding the Primary Filter is a Secondary Filter (C), comprising 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 (F) and into the rainwater tank or pipe (if attached).
5. 

• Maelstrom filter
• 3 flexible couplings (two on Maelstrom and one in box)

• Screwdriver
• 6 screws for mounting to your tank
• Utility knife
• Marker pen
• Tape measure
• Brackets (wall mount or in-tank mount)
• Drill and Hole saw (pit mount or in-tank mount)
• 600mm/24″ stormwater pit (pitmount)

Tank Top Mount

1. Determine which port on your Maelstrom’s symmetric U-bend you want to use for your water inlet and which port you want to use for your waste outlet. The filter works equally effectively in either direction, so assign each port depending on what’s most convenient for your chosen installation point.
2. Remove the existing tank screen from the opening of your rainwater tank by unscrewing and pulling it out and off the tank.
3. Snap your Maelstrom out of the mounting plate.
4. Turn your Maelstrom’s mounting plate upside down and, using your removed tank screen as a guide, trim to the nearest size by cutting in the channel as indicated. Ensure that once cut, the screw points on the mounting plate will still allow you to screw through the mounting plate into the top of the tank to provide a mosquito – proof seal.
5. Centre the mounting plate over your tank inlets and screw it to your tank top.
6. Remove the 100mm flexible coupling from the filtered water outlet (F), or you may wish to cut away the filtered water outlet from your Maelstrom in the cut channel provided to expand the outlet size and allow more water to enter your tank than the standard 100mm outlet. This is recommended if your rain harvesting system is designed to harvest 100% of your roof catchment area or if you’re in an area that experiences high peak flows during rain events.
7. Snap your Maelstrom in place through the opening in the mounting plate.
8. Loosen the hose clamp on your chosen water inlet port. Measure and cut your inlet pipe and connect it so it fits within your chosen inlet port, then tighten the hose clamp around it.
9. Loosen the hose clamp on your chosen waste outlet port. Where practical, we recommend plumbing the overflow outlet so that it directs excess water and debris to
   stormwater. Alternatively, you can cap your waste outlet with a vented flap valve.
10. Whichever outlet option you choose, measure and cut your outlet pipe, insert it in your chosen outlet port, then tighten the hose clamp around it.

Wall Mount

1. Determine which port on your Maelstrom’s symmetric U-bend you want to use for your water inlet and which port you want to use for your waste outlet. The filter works equally effectively in either direction, so assign each port depending on what’s most convenient for your chosen installation point.
2. Select appropriate brackets that can support your Maelstrom’s mounting plate.
3. Install the brackets on your wall so that they’re positioned to sit 102mm (4″) below your pipework and at least 260mm (10.2″) apart so there’s enough clearance for your Maelstrom’s filtered water outlet.
4. Snap your Maelstrom out of the mounting plate.
5. Screw the mounting plate to the brackets, ensuring it is centred.
6. Snap your Maelstrom in place through the opening in the mounting plate.
7. Loosen the hose clamp on your chosen water inlet port. Measure and cut your inlet pipe as required and connect it so it fits within your Maelstrom’s inlet port, then tighten the hose clamp around it.
8. Loosen the hose clamp on your chosen waste outlet port. Where practical, we recommend plumbing the overflow outlet so that it directs excess water and debris to stormwater. Alternatively, you can cap your waste outlet with a vented flap valve.
9. Whichever outlet option you choose, measure and cut your outlet pipe, insert it in your chosen outlet port, then tighten the hose clamp around it.
10. Loosen the hose clamp on the filtered water outlet. Measure and cut an additional length of pipe to connect your filtered water outlet to your rainwater tank. Insert it inside the filtered water outlet and tighten the hose clamp around it.
11. For best results, we recommend plumbing the other end of this pipe directly into your rainwater tank.

In Tank

1. Check that your assembled Maelstrom (including flexible couplings and mounting plate) will fit within your tank riser. There must be enough space to allow the clips on the lid to open and for the inlet and outlet pipes to be connected to your Maelstrom.
2. Identify the location of any existing inlets through the riser and use this to determine the height at which your Maelstrom will be positioned. The filter works equally effectively in either direction, so depending on what’s most convenient for your chosen installation point, you can assign either port on your Maelstrom’s symmetric U-bend as the water inlet or waste outlet.
3. Select appropriate brackets that will support your Maelstrom and install them inside the riser at least 260mm (10.2″) apart so there’s enough clearance for your Maelstrom’s outlet.
4. Mark where the outlet port will be located on the tank riser and use a hole saw to create the hole.
5. Snap your Maelstrom out of the mounting plate.
6. Screw the mounting plate to the brackets, ensuring it is centred.
7. Remove the 100mm flexible coupling from the filtered water outlet (F), or you may wish to cut away the filtered water outlet from your Maelstrom in the cut channel provided to expand the outlet size and allow more water to enter your tank than the standard 100mm outlet. This is recommended if your rain harvesting system is designed to harvest 100% of your roof catchment area or if you’re in an area that experiences high peak flows during rain events.
8. Snap your Maelstrom in place through the opening in the mounting plate.
9. Loosen the hose clamp on your chosen water inlet port. Measure and cut your inlet pipe, insert it inside the tank riser and connect it so it fits within your chosen inlet port, then tighten the hose clamp around it.
10. Loosen the hose clamp on your chosen waste outlet port. Where practical, we recommend plumbing the overflow outlet so that it directs excess water and debris to stormwater. Alternatively, you can cap your waste outlet with a vented flap valve.
11. Whichever outlet option you choose, measure and cut your outlet pipe, insert it in the tank riser and your chosen outlet port, then tighten the hose clamp around it.

Stormwater Pit Mount (Filter Pit)

1. If desired, your Maelstrom can be installed below ground level in an appropriately sized stormwater pit.
2. Determine the position of where your filtered water pipe will exit the pit and mark this position. The pipe can exit on either of the four sides or through the base. If exiting through the side wall you may wish to use a 90 degree bend to directly connect your pipe to the Maelstroms coupling.
3. Determine the position your inlet and waste pipes will penetrate the sides of the pit wall and mark. STORMWATER PIT MOUNT (600MM/24″)
4. Mark the position of the support rod holes. Support rods should be approx. 108mm (4.25“) below the bottom of the inlet/waste pipes and approx. 300mm (11.8”) apart to allow adequate support of the mounting plate.
5. Drill out all penetration holes as required and deburr.
6. Install and tighten threaded rod and appropriate nuts and washers to both inside and outside of pit wall for both supports. It is recommended to use stainless steel or galvanised components.
7. Position the pit in place and install the filtered water pipe allowing for the required length to enter the coupling. Seal around the pipe and pit wall using appropriate sealant.
8. Lower the Maelstrom in place ensuring the coupling is positioned over the filtered water pipe and tighten the hose clamps.
9. Install the inlet and waste pipes through the pit wall and into the Maelstroms coupling. Tighten the hose clamps and seal around the pipes and pit wall using appropriate sealant.
10. It is recommended to install the pit with an appropriate lid to prevent water ingress.

For best performance, check and maintain your Maelstrom on a regular basis. The required frequency of maintenance will depend on the environment in which your Maelstrom is installed. High debris areas will require more regular maintenance than low debris areas.

To determine how frequently maintenance will be required in your location, we recommend inspecting the primary and secondary filter after the first rainfall event and planning your maintenance schedule based on this initial inspection.

To clean your Maelstrom, unlatch and remove the lid.

Grasp the handle at the front of the filter and lift it upward to remove. Release the four handle clips, slide the handle off the primary filter and remove the secondary filter. Use a hose to wash out the secondary filter. If required, you can use a brush to remove any debris. Lift the mosquito proof screen out and brush or hose off any debris on either side of the screen.

Replace the mosquito proof screen, ensuring it sits securely in place. Replace the secondary filter and re-secure the handle. Return the filter to its position within the filter housing and clip it back in place, then replace the lid and secure it with the latches.

How often should I clean my Maelstrom’s filter screens?

Every environment is different, so the necessary frequency for cleaning your filter screens will vary. We recommend checking your Maelstrom filter regularly after installation to determine the rate at which debris accumulates. You can then use this information to make an informed decision about cleaning frequency. Depending upon your needs and situation, you may determine that cleaning is required monthly, quarterly, after each heavy downpour, or at a different frequency.

Do I need to modify the tank inlet when installing my Maelstrom?

No. Your Maelstrom is supplied with an adjustable flange that is designed to accommodate existing 300mm, 400mm and 500mm inlets. Simply remove the existing tank screen and trim the flange to suit the size of your inlet hole.

What head height is required when installing my Maelstrom on the inlet side of a wet or “charged” system?

Your Maelstrom filter should be installed no less than 500mm above the inlet of the tank.
When the Maelstrom overflow is connected to an outlet, for example, a stormwater discharge, the wet system head height can be reduced to accommodate low head systems. Collection efficiency is traded-off against low head height filtration.

What is the Maelstrom’s maximum flow rate?

On a wet rain harvesting system, your Maelstrom can handle water flowing at 10 litres (2.64 gallons) per second with a water catchment efficiency of 96%. It can handle water flowing at 5 litres (1.32 gallons) per second with a 99% water catchment efficiency for wet systems. Above 10 litres (2.64 gallons) per second, your Maelstrom will direct excess water to the outlet port (overflow).

Used in a wet rain harvesting system, your Maelstrom will yield 99% filtered water catchment at 5L/sec and 96% filtered water catchment at 10L/sec.

Are replacement filter bags available?

Yes. Replacement filter bags are available for your Maelstrom filter. The Maelstrom bag is designed to be reusable and can be washed and reinstalled. In the unlikely event that your bag is damaged or lost, replacements are available from Blue Mountain Co.

Can I connect multiple pipes or “lines” to my Maelstrom?

Multiple pipes can be consolidated before they reach your Maelstrom filter. However, it is important to assess the impact of consolidating these pipes to ensure that your total system flow is not restricted.

Can I install 90mm pipe to my Maelstrom?

Yes. You can use a tapered reducer or LIT (level invert taper) to connect 90mm pipe to your Maelstrom’s DN100mm inlet and outlet ports.

Can I install inlet pipes to both side ports so I have two inlets rather than one inlet and one outlet?

No. We do not recommend installing inlet pipes to both side ports. It is important that one side port is dedicated to overflow to allow your Maelstrom to perform its self-cleaning function and prevent clogging.

Can I install a first flush before my Maelstrom?

Yes. First flush diverters can be installed before or after your Maelstrom filter. If you choose to install a first flush diverter upstream of your Maelstrom, make sure you install a screened rain head before the first flush diverter so it cannot be clogged with leaves and larger debris.

Can the Maelstrom be installed in the charged area of a charged system? Ie. Can the Maelstrom be positioned below the inlet of the rainwater tank.

No. Your Maelstrom filter is not designed to carry a head of water, as the filter uses a self-cleaning gravity feed action to discard debris from the flow of water.

However, you can install your Maelstrom filter on top of your tank in place of your tank screen (or beside your tank) as the final filtering point for your wet system.

What do I do if there is a significant amount of water coming out of the debris overflow of the Maelstrom?

Check the following:

• Check the blue internal filter if there is a large amount of debris
• Check the fine bag filter if there is a lot of fine debris
• Clean either of the above filters if required

If the rainfall event is extreme, it is possible for some unfiltered water to overflow from the debris overflow port. Refer to expected flow rates section.

How do I collect the maximum amount of water from my Maelstrom?

The best way to maximise the amount of captured water from the Maelstrom is to:

• Ensure the filters are maintained periodically
• An alternative setup for the debris overflow to maximise clean water catchment is to add a small upwards bend, which will help to slow the flow of water at the debris overflow – forcing the water through the Maelstrom’s filters. In this scenario, it is recommended to maintain your filters more regularly since the debris is forced to flow over the bend.