How to Sanitize Your Water Filtration Systems After a Shutdown

Water filtration systems need to be flushed, sanitized, and cleaned after an extended shutdown or protracted disuse. Whether you have an under-sink reverse osmosis system at your vacation home or operate a seasonal restaurant or cafe, it is essential to appropriately flush your water filters before recommencing filtration. Prolonged periods of inactivity can allow bacteria to grow on the membranes and filter cartridges, especially if these filters have been submerged in water during the period of disuse. Water filtration systems are designed to be used continuously. When these systems are not in service, there is always a high potential for microbiological growth within the filters. 

Furthermore, regular maintenance and cleaning of all water treatment and filtration systems is an integral part of achieving optimal performance and ensuring the water you drink is crystal clear and refreshing. Reverse osmosis tanks should be sanitized yearly, to ensure that there is no buildup of bacterial growth in the tank. Water softener brine tanks also require periodic cleaning, to prevent clogged inlet valves, salt mushing, and diminished performance. 

If you know you are about to discontinue using your water filtration system for an extended period of time, it is a good idea to set aside weekly time to proactively flush the filters throughout the shutdown. Running water through your filters for a few minutes every few days simulates “normal” use. Performing preventative maintenance on your filtration system will help you avoid premature filter replacement after the shutdown or period of disuse expires. If you are able, turn off the water supply to the reverse osmosis system before leaving. This will help mitigate the amount of water the system is exposed to. 

How to flush your water filters if they’ve haven’t been used for 7 days or less:

For an under-sink water filtration system (like the Everpure H-300) or any whole-house or commercial water filter, you will need to flush the system for a minimum of 5 minutes. Reconnect the filtration system to the water supply, bringing the filter back into operation. Check the inlet valve and ensure there are no leaks in the system. Run water through the filter and to a designated drain for a minimum of five minutes. If your water filter has more than one outlet port, make sure you run water through each outlet port for at least five minutes. This flushing cycle will help displace any microbiological growth occurring within the water filter before you recommence using it. 

If you have a reverse osmosis system that has been unused for seven days or less, you will need to flush the membrane and the filters. First, empty out the RO storage tank. If you know that your system is going to be unused for an extended period of time, it’s a good idea to drain the tank before discontinuing use. Continue emptying the tank until the pump supplying water to the reverse osmosis system turns on. Once the pump is on, flush the RO system for 10 minutes, allowing all the water to drain before proceeding with normal operation. You can disconnect the outlet running to the air gap faucet and redirect the tubing to a designated drainage site. If the RO system has multiple outlets, ensure each outlet is flushed for at least 10 minutes. 

How to flush your water filters if they’ve haven’t been used for greater than 7 days:

If you have not used your water filtration system for more than 7 days, it is a good idea to replace all of the filtration elements in the system. This includes reverse osmosis pre-filters, carbon filters, membranes, and cartridges. Manufacturers will vary on the length of time a system can be idle before requiring full filter replacement, it is widely acknowledged that once filters have sat for longer than a couple of weeks, it is time to install a new set. Following weeks of disuse, there is a great likelihood that water stagnated within the filter media and microbiological growth is transpiring. If you’ve only been away from your home for a two-week vacation, you may not need to replace all the components of your kitchen’s under-sink RO system or your carbon block filter. However, if your restaurant’s water filtration equipment has been idling for a month, it would be unwise to resume operation with the same filters. After all, the point of filtering water is to eliminate contaminants and provide clear, clean water to you and those you are serving. Using filters with burgeoning microbiological growth defeats the purpose of filtering the water altogether. After such an extended shutdown, the filters will need to be replaced and the filtration system will need to be sanitized.

Check your equipment!: It is also worth noting you should pay special attention to equipment like ice machines, coffee makers, and espresso machines. If any water-using appliance was left with stagnant water over the course of the shutdown, it is possible that bacterial growth is occurring within your equipment. You may need to refer to the appliance manufacturer's instructions on how to best perform a cleaning cycle on these water-using appliances to eliminate this and preclude any moldy, algae tastes from fouling your beverages and discoloring your ice.

Cleaning your reverse osmosis system: 

When restarting a reverse osmosis system after a shutdown, it is important to perform a system sanitization using a product like Sani-System. After discarding the filters and performing a sanitation cycle, dip a bottle brush in a chemical disinfectant solution. Use the brush to scrub the insides of the filter housings, the membrane module, and the dispensing faucet. Bacteria and microorganisms could've potentially grown in the crevices of the equipment during the shutdown, so hand scrubbing the interior of the filtration system ensures you are taking extra precautions before installing any new filters.  

After replacing the RO membrane and pre- and post-filters, run water through the system and allow the new filters to flush. Whenever you are installing a new filter, it is important to run water through them before usage. This allows any free-floating carbon fines or flecks of media to be flushed from the cartridges. Then, run the sanitation cycle on your reverse osmosis system and tank. After you’ve finished sanitization, allow the RO system to fill the tank up completely. Drain the tank, and allow it to refill again. The system is now ready to return to operation. 

Cleaning your water softener:

If your water softener has been unused for longer than 7 days, you should manually initiate a regeneration cycle. This will ensure the ion exchange resin is properly charged and capable of softening the incoming water. After the first manual regeneration cycle, check the hardness levels of your water to ensure that proper hardness reduction is transpiring. You may need to run a second regeneration cycle to adequately flush the minerals out of the resin bed.

If the softener has been left unused for more than 30 days, it is wise to clean out the entire brine tank using a chlorine solution. This will prevent a host of common water softener problems, like salt bridges and salt mushing. Problems of this nature will severely inhibit the performance of the softener. As a result, you will not see a satisfactory reduction in water hardness, and the hardness minerals will begin to form scale deposits on your appliances and in your plumbing. 

Read our water softener maintenance 101 guide. | Learn how to troubleshoot your RO system. 

How to sanitize your reverse osmosis system: 

1. Wash your hands. Since reverse osmosis is producing water of such high purity, you want to make sure you don’t contaminate any part of your system. Ensure the area is clear of any dirt or dust, and consider wearing sanitary gloves.
2. Turn off the water supply line to your RO unit. You don’t want water spilling out all over your floor, so be sure there’s no water running to the reverse osmosis system. 
3. Disconnect any lines running to the refrigerator or icemaker. If you use RO water in your fridge to prepare crystal clear ice, make sure this is disconnected before proceeding. 
4. Open the system’s faucet and drain the tank. You want to make sure you drain the system entirely of water. Running the faucet will also depressurize your storage tank. Leave the faucet open until all water drains, then shut it off. 
5. Remove all pre-filters and the membrane. Open up all the filter housing and remove the filters. There should be no filters or membranes inline your system during the sanitization process except for the postfilter. If you are exchanging them for new filters, discard the old filters at this point. 
6. Reconnect the filter housings to the system. Replace all housing back on the system, except for the pre-filter housing. 
7. Pour the sanitizing solution into the pre-filter. We recommend using the NSF-certified sanitization solution called Sani-System. It is the only EPA approved RO sanitization solution, and it requires no measuring or mixing. It doesn’t contain any chlorine and will neutralize any bacteria growing within your tank. Attach the pre-filter housing back to the system. 
8. Turn the water supply back on. Allow the storage tank to fill up with water. Turn on the RO faucet until water begins to flow out, alerting you the tank has filled. Turn off the faucet. 
9. Allow the solution to sit. This will vary based on the sanitization solution you are using. If you’re using Sani-System, you need to wait for at least one minute. 
10. Flush the entire system. Open the faucet and allow the reverse osmosis system to flush itself. Wait around five minutes. Allow the tank to again fill with water before flushing it a second time to ensure all traces of sanitization solution exits the tank. 
11. Disconnect the water supply and drain the system. Disconnect the water supply and open the faucet. Wait until all the water drains out of the system and the tank completely depressurizes. 
12. Replace all the filters and membranes. This is a great time to replace your filters, as pairing the maintenance with filter replacements ensures your system is regularly cleaned and your filters are replaced on time. 
13. Reconnect the water supply. If you disconnected any ice-maker or refrigerator connections, reattach them at this time. Allow the storage tank to refill with water, and you’re ready to use your reverse osmosis system again.

What is Sani-System?

Sani-System is a liquid sanitizer, and the only NSF & EPA approved reverse osmosis system sanitizer. Sani-System can also be used to disinfect water softeners, water coolers, water storage tanks, and well pressure tanks. Sani-System does not use acids, chlorine, or oxidizers that can be damaging to the reverse osmosis system’s equipment. Sani-System comes conveniently pre-measured in individual packets, and can be added to pre-filter housings or softener brine well’s with the aid of a simple syringe. 

Do I need to replace my UV lamp after a shutdown?

If your UV system had no flow throughout the shutdown, it is possible that the lamp was damaged and will need to be replaced. To be safe, you should use a water test to check the bacteria content of your water. While many systems are equipped with monitors and alarms that are programmed to alert homeowners when performance has faltered, a shutdown presents unusual circumstances. Perform a water test to ensure that the lamp's germicidal properties haven't been compromised. If you are aware that the system needs to be shut down for an extended period of time, use a shut-off valve on either side of the UV system to prevent any untreated water from passing through the system and into your home, restaurant, or business. 

Normally, you should not turn off your UV purification system during periods of disuse. Ultraviolet purification systems utilize UV lamps to neutralize bacteria. These lamps usually have a lifespan of around 9,000 hours (or, a little over a year’s length of service life). The bacteria-neutralizing properties of the lamp are powered by beads of mercury found within the UV lamp. Over the course of the year, the mercury will slowly deplete, and the lamp will gradually lose its disinfecting power. Turning the system on and off actually hastens this process. The energy used to initialize the lamp eats away at a small portion of this lifespan. If you are frequently turning the system off and on, you can end up dramatically reducing the life of the lamp.

However, there is a larger risk when turning off your UV system on and off. If you are using ultraviolet purification methods on your water, you are likely drawing water from a source that may contain bacteria or microorganisms. If you accidentally resume water use in your home or business without first passing it through the UV lamp, you risk exposing yourself and the entirety of your plumbing to waterborne bacteria. In this instance, most manufacturers recommend you initiate a whole-house disinfection process to ensure that any microbiological contaminants are purged from your plumbing.

The primary reason water filters require replacement after extended shutdowns is because they are exposed to water and at risk of growing bacteria on their membranes and media. UV systems are sterile and used explicitly to irradiate microorganisms and pathogens with UV-C rays. They are not at risk of becoming contaminated during brief or prolonged periods of inactivity. However, if there is no flow passing through the system, it is possible the lamp could be damaged and diminished in its disinfection capacity. 

Learn how to maintain your UV system. | Explore how to remove bacteria from water. 

Do I need to flush my new water filter?

Yes, if you are replacing your system’s water filters, it’s essential that you flush them before putting them in service. If you’ve ever replaced a refrigerator filter, you’ve likely experienced the loose carbon media that appear in your water after replacing the filter. This does not mean the filter is defective or broken, this is entirely normal for any new carbon-based media cartridge. New cartridges also contain air, so flushing them will replace this space with water. This ensures that both your filtration system and equipment can operate at peak efficiency. 

Many restaurants, hospitality industries, and coffee shops use Pentair’s Everpure line of filtration products to provide their clientele with the highest quality beverages, fountain drinks, and hydration. After an extended shutdown or the lifespan of the filter has ended, Everpure filters are simple to replace and flush.

How to replace an Everpure filter: 

1. Shut off the water supply. Before replacing any Everpure cartridges, first ensure the water source has been turned off. You don’t want to end up flooding your floor! Turn the valve on the water intake line until it is completely closed. If your system has a flushing valve, open it to relieve pressure.
2. Turn off the power to any equipment. If your filter is servicing an ice machine, espresso machine, or coffee brewer, ensure that the equipment is disconnected from its power source. 
3. Remove the old filter cartridge. Twist the old cartridge a quarter to the left, until the rotation stops. Now, pull the filter down and out of the system. Using a clean rag, wipe out the inside of the system where you plan on attaching the new cartridge. This helps eliminate any excess dust and keeps the system clean. 
4. Align the new cartridge with the system. Make sure the new cartridge’s lug is aligned with the label on the head. 
5. Insert the new cartridge into the system. Turn the new filter a quarter to the right, until the filter stops rotating easily and is snugly fit into the system. Take this time to inspect the o-rings of the system to make sure none are loose or cracked and in need of replacement.
6. Turn the water back on. You will need the water to help flush your new filters.
7. Flush your new filters. Allow water to flow through the new filters for a minimum of five minutes to flush any air and loose carbon fines from the filter. You can connect a drainage hose to the system and divert the flushed water to a drain or a sink. 
8. Turn the equipment back on. Make sure the flushing valve is closed, and then turn on the equipment the filter is servicing. You are now ready to use your equipment again. 

Everpure also offers a sanitation cartridge to introduce cleaning agents into your Everpure system. A shutdown is a perfect time to make sure your system has been thoroughly disinfected. The sanitation cartridges fit into Everpure filter heads and are the perfect way to distribute sanitization throughout your water filtration systems, and water-using appliances. Just like sanitation is integral to the maintenance of both water softeners and reverse osmosis systems, regularly cleaning your Everpure systems will ensure the water being produced is pristine. It is possible for bacteria to grow within poorly maintained and improperly serviced systems, regardless of a shutdown. 

These sanitizing cartridges also can be used to introduce ScaleKleen into your water filtration systems. Scale is caused by water hardness minerals (magnesium and calcium). In many parts of the world, water is naturally very hard because of the geographic makeup of the aquifers. These minerals will emerge from the water and cluster, creating limescale build-ups on appliances and fixtures. Scale can reduce water pressure, corrode equipment, and choke out the heating elements of appliances. Since scale precipitates even quicker in hot water, appliances like steamers, coffee brewers, showers, and water heaters are even more prone to the destruction brought on by hard water. ScaleKleen is a proprietary de-liming agent that eliminates scale deposits from water filtration systems quickly and effectively. Introducing ScaleKleen into your equipment is an excellent way to protect them from damage, ensure you are not voiding warranties, and restore your equipment to peak performance.  

| Learn more about Everpure’s exceptional commercial water filtration. |