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.
After an extended shutdown or period of lengthy disuse, it’s important to flush, clean, and sanitize water filtration systems. Before filtration can recommence, it’s essential to complete this task because bacteria can grow on filter membrane surfaces. Every water filtration system is designed to work in a continuous manner and prolonged periods of disuse will compromise their performance and efficiency. In this article, we will focus on filtration, reverse osmosis (RO) filters, and water softener systems.
Advanced Notice of Length Disuse
If you know in advance that you won’t be using your water treatment systems for some time, it’s possible to simulate their use to keep them running efficiently. Spend some time running water through the RO system and filter every week or so. Then turn off the water supply before you leave the building to prevent exposure to water. Getting some preventative maintenance when you’re using the systems regularly is a good decision.
Dealing with Shorter (Less Than a Week) Issues
Water Filters
Commercial grade water filters should be flushed for at least five minutes when you’re ready to start using them again. The inlet valve should be checked for leaks and water run through the filter and out into the drain. If there are multiple outlet ports each one needs to be flushed for the minimum of five minutes. The flushing will expel any microbiological growth that may have accumulated inside the equipment and connecting pipes.
RO Filters
The pre-filter, membrane, and any post-filters need to be flushed and the storage tank should be emptied. Draining the tank for extended periods of disuse is a great idea and the tank should be emptied until the supply pump turns on. At this point flush the entire system for at least ten minutes and allow the water to fully drain. Then disconnect the outlet that connects to the air gap faucet and place that tube in the drain. If your RO system has more than one outlet, this process should be repeated for each outlet.
Water Softeners
Up to seven days, there are no special requirements needed to keep your water softener system working properly. The regeneration cycles will continue and you may want to shut the system down to save water.
Dealing with Longer (More Than a Week) Issues
Water Filters
After seven days without using a water filtration system, it’s a good idea to replace the components. The various elements of the filtration system, including cartridges, carbon filter blocks and more require replacement after a set period. This will vary depending on the manufacturer, but generally speaking, it’s better to replace any components that have not been used for seven days up to a couple of weeks. After that time the filter media will have stagnated and degraded to the point where it cannot perform its intended function. At this point, it’s likely that significant microbial growth has taken place and flushing will be ineffective.
RO Filters
The same advice is equally applicable for RO filters and all the components of an under sink point-of-use system need to be replaced. This will include the sediment pre-filter, the membrane filter, and the granulated activated carbon filter too. After these components have been replaced, it’s important to drain, clean, and sanitize the RO storage tank. A sanitization product can simplify this process and the internal sides of the filter housings can be scrubbed with a bottle brush dipped in a suitable disinfectant. The membrane module, dispensing faucet, filter housings, and storage tanks must be clean and free from bacteria. After the sanitization, the new filter components can be installed and the RO filtration system is ready for use.
Water Softeners
After seven days, it’s necessary to initiate a manual regeneration cycle to provide sufficient charge to get the ion exchange resin media ready to soften water. After this initial regeneration cycle, the water hardness should be checked to ensure that softening is taking place. A second regeneration cycle may be required to flush any remaining minerals out of the resin media bed. After thirty days, the brine tank must be cleaned with a chlorine solution and salt mushing and bridges need to be dealt with.
What About Ultraviolet UV Purification Systems
The UV lamp with no water flow passing can be damaged and a replacement may be required. A water test to ascertain the level of bacteria and other microorganisms is advisable but the better systems have built-in monitoring and alarm systems. If an extended period of disuse is expected, shut-off the water valve before and after the UV lamp. This will prevent any treatment and untreated water cannot pass through the system at all. Under normal circumstances, there is no need to turn off your UV purification system.
A UV lamp has a 9,000 hour lifespan (approximately one year) and the lamp works with mercury beads which will not decay for at least a year. After this time, the antibacterial properties of the UV lamp will degrade and the water will be less clean. Some people try to extend the lifespan of their UV lamps by turning them off when they are not in use. This has the opposite effect, the initialization of the lamp actually reduces the lifespan which makes this a counter-productive strategy. Leave the lamp on all the time, but shut-off the water if you’re going away for more than a couple of days.
Should I Flush a New Water Filtration System?
Yes, when the filters are replaced they should be flushed before they are installed in your new system. If you’ve ever replaced a filter jug cartridge or a refrigerator filter, you may have noticed tiny particles of loose carbon in the water. This is normal and you will notice this phenomenon in a point-of-use or whole house system too. The new filters usually contain a certain volume of air that’s displaced when water fills those spaces. This in turn can loosen and expel a certain volume of filter media but it will settle down quickly.
If you want to learn more about servicing, maintenance, and sanitization of your home water filtration systems, contact your local water treatment specialist today.