WaterMark Ultraviolet Water Sterilisation System 50L/m Whole House UV 316 Stainless Steel (GT7-8K)

Please note that the GT7-8K UV System has been discontinued.
To buy replacement parts for this system, please see the links below.

***Please note that there are two styles for the GT7-8K System per the below image.***

Type A: Domed Style GT7-8K System - Replacement Parts Below

• 1x 7-8K UV Lamp (Replace Every 12 Months)
• 1x 7-8K Thimble (Replace Every 1-2 Years)
• 1x 7-8NSF O-Ring (Replace Every 1-2 Years (along with Thimble))
• 1x 7-8K Power Source (Ballast)

Type B: Twin Nut Style GT7-8K System - Replacement Parts Below

• 1x 7-8K UV Lamp (Replace Every 12 Months)
• 1x 7-8K Thimble (Replace Every 1-2 Years)
• 2x 7-8NSF O-Rings (Replace Every 1-2 Years (along with Thimble))
• 1x 7-8K Power Source (Ballast)

The GT7-8K has now been superseded by the NEW Watermark Ultraviolet Water Sterilisation System 50l/M Whole House Uv 316 Stainless Steel (7-9K) System.

Full Australian WaterMark Certification

This Water Filtration System is certified to WaterMark Standards AS/NZS 3497 under Certificate Number 23247. WaterMark is the standard that is required by law for a qualified plumber in Australia to install any item on municipal town water. All products used under this certification will give you peace of mind knowing that your water filter complies with Australian plumbing codes. Our WaterMark filtration systems are hand assembled here in Australia and are batch tested to ensure quality and workmanship for your filtration products.

Ultraviolet Sanitation

UV Water Sanitation is by far the most important filtration process when it comes to rainwater treatment. Rainwater harbours bacteria of all types but in some cases, much more harmful bacteria may be present in the tank. E-Coli is a common bacterium in tank water and is due mostly to Frogs in and around your tanks/catchment. Ultraviolet sanitation works by breaking down the cell wall of a micro-organism allowing oxidation to occur which in turn prevents the bacteria from multiplying until it is finally eradicated. Ultraviolet filtration is a chemical-free solution to water sanitation creating no by-products in the water.

​We recommend adding the optional UV Thermal Relief Valve for any situation where the UV system is installed and water is not continuously running through the system. This will prevent the UV system from overheating and damaging the seals 

Kit Contains

• GT7-8K               WaterMark Whole House UV System 40W | 1” Ports
• GT7-8-BRK (x2)   1 Pair of Aluminium Mounting Clamps + Screws
• GT7-8K-Lamp      840mm 4 Pin 40W UV Lamp
• GT7-8K-Thimble   895mm Quartz Thimble 24.5mm*OD
• GT7-8K-PS          UL Certified Ballast 40W Australian Plug + Earth Cable
• GT7-8NSF-OR      NSF/ANSI 42 Compliant O-Rings Suit 24.5mm*OD

Features

• Commercial Grade Electropolished 316 Stainless Steel Chamber
• Visual & Audible Lamp Failure Alarm
• 1” BSP Threaded Male Connections
• Strong Aluminium Mounting Brackets – Surrounds Chamber
• High Intensity UV Lamps – Up to 50L/min @ 30mJ/cm²

Water Pre-Treatment Specifications

• Hardness              < 120 mg/L
• Turbidity              < 1.0 NTU
• Iron                    < 0.3 mg/L
• Manganese          < 0.05 mg/L
• Tannins               < 0.1 mg/L 
•  Filtration            < 5uM Particulate Filtration

UV System Maintenence Notes:

Ultraviolet systems are rated based on a dosage level of UV-C radiation into the water (mJ/cm²), with 30mJ/cm² being the standard level of disinfection and a minimum dose of 40mJ/cm² required to comply with Australian Drinking Water Guidelines. Our lamps are rated with a 9000 hour (1 year) lifespan, after which point the lamp will naturally degrade and the level of radiation produced by the lamp cannot be guaranteed.

The UV lamp sits inside a quartz thimble, which protects the electrical components of the lamp from making contact with the water. We specifically use quartz (fused silica) for this application because it is strong, exhibits thermal resistance, and has excellent UV transmission properties.

However, over time, metal ions fused within the silica structure of the quartz thimble interfere with the UV-C radiation produced by the lamp, which reduces the UV transparency of the glass and causes it to become fragile. This process is called solarization.

Tannin, bio-film, algae, and scale can also build up on the outside of the glass thimble, further preventing ultraviolet light produced by the lamp from penetrating through the thimble, and impairing the system's ability to sanitize the water passing through.

Thus, we recommend replacing the lamp every 12 months, and the thimble every 1-2 years.