WaterMark Ultraviolet Water Sterilisation System 50L/m Whole House UV 316 Stainless Steel (GT7-9K)

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 mostly due to frogs living in and around your tanks/catchment. Ultraviolet sanitation works by breaking down the cell wall of a micro-organism, thus 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

• GT7-9K               WaterMark Whole House UV System 40W | 1” Ports
• GT7-8-BRK (x2)   1 Pair of Aluminium Mounting Clamps + Screws
• GT7-9K-Lamp      840mm 4 Pin 40W UV Lamp
• GT7-9K-Thimble   895mm Quartz Thimble 23mm*OD
• GT7-8K-PS          UL Certified Ballast 40W Australian Plug + Earth Cable
• GT7-2NSF-OR      NSF/ANSI 42 Compliant O-Rings Suit 23mm*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

When is a Thermal Relief Valve Required?

A Thermal Relief Valve is a temperature-sensitive valve that opens 56°C, draining water from the UV chamber. A Thermal Relief Valve is recommended on installations where there can be prolonged periods of time without water flow, as the excessive build-up of heat in the chamber may cause the O-ring to deform and fail, causing leakage which can come into contact with the lamp/power supply, thus causing damage. Generally lower wattage systems (less than 48W) such as the GT7-9K do not reach extreme temperatures under normal conditions; however, under certain circumstances, it may be necessary to install a TRV to limit the temperature. Most use-case scenarios with this system will not require a Thermal Relief Valve - however, if you think you might require one, please contact us prior to purchase so that we can determine if this is a requirement. Note: it is not recommended to leave the system and TRV in operation and unattended for extended periods of time (ie. more than 48 hours) - in such circumstances the system is best turned off.

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.

GT7-9K System - Replacement Parts Below

• 1x 7-9K UV Lamp (Replace Every 12 Months)
• 1x 7-9K Thimble (Replace Every 1-2 Years)
• 1x 7-2NSF O-Ring (Replace Every 1-2 Years (along with Thimble))
• 1x 7-8K Power Source (Ballast)