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.

A water filtration system must be flushed and sanitized after a period of lengthy disuse or an extended shutdown. If you have a reverse osmosis (RO) system at your vacation home or a seasonal business, it must be flushed before any new filtration occurs. Over periods of disuse, bacteria can grow on the filter cartridges and membranes. This is especially true if those filtration components have been submerged under water for the entire time. Most modern water filtration systems are designed for consistent and continuous use. If a system is not used in this way, there is an increased risk of microbiological growth within them. Let’s take a closer look at this issue in more detail to help you secure a clean source of water for your home and/or business.

Annual Water Filter Sanitization

Water treatment experts recommend that a water filtration system is regularly cleaned and maintained. Ideally this should be annually scheduled to ensure that the water is clean and fresh and to achieve optimal performance. A RO filter storage tank should be sanitized every year to remove any bacterial growth that may be lurking there. Many people are unaware that this can affect their water softening systems too. The brine tank needs regular cleaning to keep the inlet valves clean, prevent salt mushing and to maintain optimal performance. If you want to learn more about annual maintenance and cleaning for your home water treatment systems, contact your local specialist.

Dealing with Extended Shutdown Periods

As you can see, it is important to schedule annual cleaning and maintenance. But, if you know that your systems will be shut down for a while you can take steps to minimize bacterial growth and protect your equipment.

First, set a time each week to flush the filters during the shutdown when this is possible. If you have a vacation home in a separate location, the caretaker, a neighbor or a handyman can take care of this for you. When the water is run for a few minutes every 3 or 4 days, it will simulate the typical use for that system. The filters won’t dry out and the bacteria will not be able to linger for long enough to grow rapidly.

Next, you can perform some preventative maintenance to protect your water filtration system. Turn off the water supply to the RO system before you vacate the property. This will limit the contact between the filter membrane, storage tank and water supply. This will reduce the risk of bacterial growth and it will mitigate the risk of a premature filter change when you are ready to use the system again.

Flushing Water Filters Up to 7 Days

If your water filters have not been used for up to 7 days, you must flush the system for at least 5 minutes. Start by reconnecting the filtration system to the water supply. Then check the inlet valve to make sure there are no water leaks. Run the water into the drain and if the filter has multiple outlets they must all be run to the drain for the full 5 minutes or longer. This flushing cycle is essential because it displaces microbiological growth that could be located inside the water filter.

A RO filtration system needs to be handled a little differently because the filters and membrane can be affected. First, empty any remaining water out of the under sink storage tank and if you’re prepared, this should have been emptied in advance. Empty the tank until the RO pump turns on and then flush the system for 10 minutes. The water must drain fully before any normal filtration operations can process. Disconnect the outlet that runs to the air gap faucet and place it in the drain. If your RO system has more than one outlet make sure they are all flushed for a minimum of 10 minutes.

Flushing Water Filters Over 7 Days

If your water filtration system has not been used for longer than 7 days, the system should be handled in a different way. At this point, it’s a good idea to replace each filtration element in the system to ensure cleanliness. The will include components, such as the pre-filters, filter cartridges, the membrane filter, and any carbon filters. Manufacturer idle times can vary a great deal within filtration product ranges when full filter replacements are concerned. But, it’s an acknowledged fact that filters in disuse for two weeks or longer should be replaced entirely. This is because stagnant water can lead to microbiological growth within the span of a single two week vacation. If the period of disuse is a month or longer, it’s important to replace the components and sanitize the entire system.

Checking the Appliances

The water using appliances, including your: coffee makers, espresso machines, ice machines, and more, need to be checked. If stagnant water has been left in these appliances, they may be affected by bacterial growth. Most modern appliances have a cleaning cycle to mitigate the risk and full instructions on this feature should be in your owner’s manual.

Cleaning the RO Filtration System

After an extended RO filter shutdown, you need to use a sanitization product to thoroughly clean the system. Discard the filters, dip a small brush in your chosen cleaning products and scrub the inner surfaces of the filter housings. Scrub the membrane module and the faucet that dispenses the treated water. These areas have deeper crevices that can harbor bacteria and other potentially harmful microorganisms. Take your time to cover every surface to ensure that the unit is fully clean before new filters are installed. When the pre-filters, membrane filter, and post-filters are replaced, it’s time to flush the system. Flushing water through the filters removes any remaining free-floating small pieces of carbon that could be loose inside the filter. Now you can run the sanitization cycle, after the storage tank fills, drain it and refill it again to ensure that the system is ready to use.

If you want to learn more about maintenance, cleaning, and sanitization for your water filtration systems, contact your local water treatment specialist.