Twin Whole House Water Filter System | 20" x 4.5" High Flow System | WaterMark Certified (GT1-9WM)

Twin Whole House Water Filter System — 20" x 4.5" High Flow, WaterMark Certified (GT1-9WM)

Whole-of-house filtration on full-sized 20" x 4.5" UV-resistant housings. The large cartridge size gives you the surface area and contact time you need for real chemical reduction, and the flow rate to do it without the family noticing a pressure drop in the shower.

Choose your configuration

Whole-house housings are shipped to you empty. Rather than leave you to work out which cartridges to buy, we've matched them for you — pick the option for your water source and it arrives ready for your plumber to fit.

• Complete — mains water ($546)
  System plus a 5 micron washable pleated sediment cartridge and a 5 micron coconut carbon block. Sediment first to protect the carbon, then chlorine, taste and odour reduction. The standard setup for town water.
• Complete — rain & tank water ($572.50)
  System plus a 5 micron washable pleated sediment cartridge and a 5 micron silver impregnated bacteriostatic carbon block. The silver treatment stops bacteria colonising inside the carbon itself, which is the common failure on tank water.
• Housing only ($360)
  The system on its own. Choose this if you already know the cartridges you want, or your plumber is specifying them.

Filtering rain, tank or bore water? Filtration alone does not make untreated water safe to drink — carbon does not kill bacteria, viruses or parasites. Tank and bore supplies need UV sterilisation as well. Talk to us before you order and we'll tell you honestly what your water needs.

What's in the box

• Twin whole house filter system with bracket pre-installed
• Opening spanner
• 2 x 1/4" pressure gauge hole plugs
• Instruction and warranty sheet
• Cartridges, on the two Complete configurations above

WaterMark certified

Certified to WaterMark Standard AS/NZS 3497 under Certificate Number 23247. WaterMark certification is what the law requires before a licensed plumber can install a water filter system in Australia — so this system can be connected legally and to code.

Installation

This system must be installed by a licensed plumber. We're licensed plumbers ourselves — Wahoo Plumbing, QBCC 15256568, working the Sunshine Coast since 1997 — so if you're between Caloundra and Noosa or all of Moreton Bay area, we can quote the install and fit it properly, with a bypass so you still have water when it comes time to change cartridges. Anywhere else in Australia, any licensed plumber can fit it and the instructions come in the box.

Technical specifications

• Dimensions: 70cm high, 41cm wide, 20cm deep
• Cartridge size: 20" x 4.5" — takes any standard cartridge, you are not locked into proprietary filters
• Ports: 1" female BSP inlet and outlet
• Pressure: 0 to 620 kPa
• Limit pressure: 500 kPa maximum
• Temperature: 0.5°C to 37.8°C
• Max flow: 60 litres per minute
• Initial pressure drop: 10 kPa at 57 litres per minute
• UV resistant — can be installed in direct sun or shade

Cartridge changes

Plan on an annual change on mains water, sooner if you're on tank water or your pressure starts dropping off. Turn off the inlet, press the pressure relief valves, unscrew the sumps, swap the cartridges, screw back up and turn the water on. Water can look cloudy or feel slightly slippery for the first few minutes afterwards — that's dissolved oxygen and fines from the new carbon, and it clears quickly.

We stock the full replacement range for this system in both 20" x 4.5" sediment and carbon.