With more than 30 years’ experience in the residential and commercial water treatment space, Mark Nelson is a Class 1 Drinking-Water Operator and a CBWA (Canadian Bottled Water Association) Certified Plant Operator. As founder and president of Nelson Water in Ottawa, Mark focuses on dealing with challenging water treatment system designs for problem water. He also heads the largest water bottling plant in the city of Ottawa with a delivery network throughout the Valley.
Installing an ultraviolet (UV) purification system to treat your incoming water is a smart decision. The use of IV-C radiation to kill harmful bacteria, pathogens, cysts, and unsafe bacteria is efficient and well understood. But, like any complex equipment, the UV system will require some annual maintenance to operate efficiently. Changing the UV lamp, cleaning the quartz sleeve and general maintenance is the best way to protect your investment. In this article, we will take a closer look at UV water purification system maintenance in more detail.
The Need for UV Lamp Replacement
UV lamps are germicidal, the UV-C radiation prevents the replication of microorganisms which leads to disinfection. This process is fueled by beads of mercury which create electrical arcs that emit the required UV-C light radiation. This wavelength is required to neutralize the bacteria and over time the effectiveness of the mercury will degrade. Exposure to high levels of mercury can be dangerous, but the UV lamp only contains minute quantities. The mercury never comes into direct contact with the drinking water and it poses no health risks. But, the burnt out UV lamp bulb must be disposed of in a responsible manner to prevent mercury contamination. Check locally for a light-bulb recycling drop-off point or check with the manufacturer to see if they offer a mail back kit.
Changing the UV Lamp
For easy reference, the UV lamp should be replaced annually and they tend to have a lifespan of around 9,000 hours. So, the lamp should operate for approximately a year and an extra week before a replacement is required. It’s always a good idea to have a spare UV lamp bulb on hand for any unfortunate accidents and a replacement as needed. This is important, if the UV lamp bulb fails there will be no disinfection and your drinking water is not guaranteed to be protected against microbial health threats.
Changing the O-rings
When you change the UV lamp bulb, it’s important to change the o-rings at the same time. The o-rings create the watertight seal for a leak-free system and over time they tend to degrade, weaken and crack. If new o-rings are fitted, you can ensure that the water will not escape the chamber to damage the electrical components.
The UV Purification System Alarm
Many UV purification systems have an alarm that will sound when the lamp is not emitting sufficient UV-C radio waves to disinfect the water. This is a handy feature, it’s all too easy to forget about a change unless you set a reminder on your phone or a physical calendar. If your system has this feature, resist the temptation to ignore or delay the UV lamp bulb change.
Turning Off the UV System
Some people believe that they can prolong the lifespan of their UV lamp by turning it off when the system is not required. This is a bad idea, the UV system should be left on because if you forget to turn it back on, you may be receiving contaminated water. Another good reason to keep the system running is that the lifespan of the UV lamp is actually shortened when it’s turned on and off again continuously. The only reasonable scenario for turning off the UV purification system is a seasonal home or cabin. If you’re not using the home for most of the year, it’s probably a good idea to turn it off when you leave. But, it’s important to track the use carefully, and changing the UV lamp every other year is probably a good idea.
The UV System Quartz Sleeve
This is a glass tube that allows the UV-C germicidal wavelength to pass through the glass and into the water. The quartz sleeve is designed to be extremely transparent to make the UV light exposure efficient for disinfection purposes. Regular glass would not be sufficiently transparent for this purpose and the microorganism would be unaffected. The quartz sleeve also serves a critical secondary function to separate the incoming water stream from the electricity used to power the system.
Understanding the Quartz Sleeve
The quartz sleeve must be clean and clear or the UV-C radiation cannot penetrate and disinfect the incoming water. If the glass surface is dirty or cloudy, it will give the bacteria and any other microorganisms somewhere to hide from the UV light. This will allow them to slip through the disinfection process which will degrade the water quality. It’s worth noting at this point that hard water can leave deposits of calcium and magnesium on the surface of the quartz sleeve. The formation of scale will impede the transparency of the sleeve which will also prevent the penetration of germicidal UV light. If you have hard water, you may want to consider a pre-filter or water softener to protect and support your UV purification system. Remember that the UV light system cannot remove dissolved minerals and other contaminants that are not microbial in nature. Better quality water will extend the useful lifespan of your quartz sleeve, plumbing pipes, and water using appliances.
Cleaning the Quartz Sleeve
The quartz sleeve can be washed gently with a soft cloth that’s soaked with a mildly acidic cleaning agent such as white vinegar. This removes any accumulated scale, stains, discoloration, and cloudiness that can impede the passage of UV-C light. It’s important to wear gloves to protect the glass surface from oils on your fingers that can blemish and damage the quartz sleeve. The cloth must be soft, abrasive surfaces will cause scrapes and scratches that will make the sleeve ineffectual.
Replacing the Quartz Sleeve
The quartz sleeve should be replaced every 2-3 years to ensure adequate disinfection. After this time, the sleeve will be harder to clean and the transparency cannot be maintained. Depending on your incoming water quality, you will notice if your replacement schedule is at the upper or lower ends of the 2-3 year expected lifespan. Having a spare quartz sleeve on hand is a good idea because they are fragile and easy to damage.
If you want to install a UV purification system in your home or your existing system requires some essential maintenance, contact your local water treatment specialist.