How often do you think about the interior of your reverse osmosis (RO) storage tank? We know our water filtration systems are working well, removing contaminants and providing us with clear, crisp-tasting water that we enjoy. However, the storage tank is often neglected. Maintaining your RO water tank at home is something you may think requires specialized skills, but it’s simple to keep your tank clean with a few basic steps.
If you’ve noticed that your water tastes a bit “off” recently or the flow of water from your filter seems sluggish—as slow as a snail—it’s time to take care of your water purifier tank.
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Preparation and Tools Required
Before you start tackling any pipes, make sure to prepare properly. Start by reviewing your equipment. Identify the main RO unit, locate the storage tank (usually a large metal or white plastic container located under the sink), and identify the check valves. Being aware of the equipment locations will help prevent a lot of confusions in the future.
Now, gather the necessary materials needed for cleaning. Most of them can be found in your kitchen pantry. The tools required are:
Mild dish soap: Any regular dish soap with degreasing properties.
White Vinegar or Hydrogen Peroxide: Vinegar helps in softly descaling (breaking down the layer of hard mineral deposited in the tank), whereas hydrogen peroxide (3-5%) serves as an effective germicide. Please check your user manual to check what is recommended for your storage tank material.
A soft sponge or cloth (non-abrasive): To clean the tank without damaging its surface. Do avoid using steel wool or abrasive cleaners.
A bucket to hold dirty water.
Clean towels: In case there are any spills during the process.
Don’t forget to wear your personal protective equipment. Wear your rubber gloves. If you are using a spray bottle with your cleaning solution, consider wearing eye protection as well (optional, usually not required). Good eye care can help to prevent splashes causing discomfort to your eyes.
Note (optional): Keep your reverse osmosis (RO) system manual handy. If you get stuck with any complex part during its operation or maintenance, refer to the manual. The manual contains product-specific detailed guidelines necessary for the effective functioning of your particular RO system.
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Choose How Often to Clean
How often should we perform this? Although there isn’t a “one size fits all” time frame for cleaning, it’s a good idea to do so every six to twelve months. Always having clean water should be our goal. Don’t wait for the calendar to remind you when to clean. Follow your instincts or do as required.
If your water smells of rotten eggs or tastes metallic, take notice. Cloudy or slimy residue in the storage tank or excess slime in the filter means that you have neglected to clean your water purifier for quite a while. Reduced water flow coming out of your faucet is due to low water pressure issues in the tank or clogged filters. Don’t ignore these signs—your water filter needs to be cleaned.
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Step-by-Step Cleaning Process
Step 1: Power down and isolate
Safety should be our number one concern. Switch off the RO system completely. Identify the inlet valve—this is usually a small valve connected to the water supply line coming from your wall. Close it tightly. If your system has a switch or plug, disconnect the power source. This will prevent the pump from being activated accidentally while we work on it. It also stops any water from flowing into the tank while we empty it.
Step 2: Drain the storage tank
You need to get rid of the old water. Open the purifier faucet on your sink and let the water flow until it stops completely. This step serves two purposes: emptying the tank and relieving internal pressure. RO tanks are pressurized to force water outwards. Attempting to open a pressurized tank can lead to difficulties and messes. Relieving the pressure makes subsequent tasks easier. Once the flow has stopped, close the faucet.
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Step 3: Prepare cleaning solution
Now it’s time to prepare your cleaning solution. Depending on what you need, you have two good options available. Option A is the vinegar mix. Mix 1-2 tablespoons of white vinegar with 1 gallon of water. It helps in removing limescale deposits and light mineral deposits.
Option B is more effective. Mix 3-5% hydrogen peroxide with 1 gallon of water. It is effective in cleaning and killing resistant bacteria. Please refer to the user manual before using hydrogen peroxide. Certain manufacturers prefer vinegar over chemical cleaners.
Step 4: Access the tank interior
You need to access the tank interior. Disconnect the tank from the equipment. There should be a valve at the point where the pipe connects to the tank. Turn it off or detach the tube carefully. Place the tank in a sink or on a towel.
Some water tanks have a removable water storage tank cap. If your tank comes with one, remove it. If your tank is sealed (as some compact types are), you won’t be able to open the top. If you can’t remove the cap, you’ll need to pour the cleaning solution into the inlet port and shake the tank.
Step 5: Clean interior surfaces
Take a soft sponge and dip it into the cleaning solution. Clean the interior sides of the tank thoroughly. Pay particular attention to the bottom of the tank, as that’s where sediments and sludges accumulate. If your tank has a bladder (the rubber bag inside), gently clean it as well. Be cautious not to puncture the bladder.
Use a soft brush to clean tight spaces such as corners. Your aim should be to remove any visible biofilm or dirt on the equipment. Do not use steel wool or rough scrubbers, as they can scratch off the plastic tank coating or stainless steel. Scratches on the tank surface provide good habitats for bacterial growth.
Step 6: Rinse thoroughly
Once you have cleaned the tank, you need to rinse it. This step is very important. You don’t want to drink vinegar or soap. Rinse the tank several times with fresh water. Fill it up, swish the water around, and empty it out. Repeat this process until there is no longer any sign of the cleaning solution left. Any residues left behind can affect the water’s taste for days to come. Allow adequate time for this part of the task. It is better to over-rinse rather than to insufficiently rinse.
Step 7: Sanitize (optional but recommended)
To provide additional safety measures, sanitize the tank thoroughly. This is highly recommended, especially when you see mold or slime earlier in your tank. You can buy specialized water tank cleaning products online. If using bleach, ensure you get food-grade one and use a small quantity diluted thoroughly.
But many experts suggest not using bleach, as it can damage the rubber parts. A vinegar scrub gives good sanitizer results and is easily available at home. If you use any sanitizer, give your tank one final rinse with plain water.
Step 8: Dry and reassemble
Before reassembling the tank, let it dry first. The presence of moisture leads to bacterial growth. You can allow it to air dry or clean it with a dry, clean cloth. Upon drying, attach the tank lid firmly. Check the rubber o-ring or gasket. If damaged or old, replace it.
A faulty seal can lead to water seepage through the filter. Re-attach the tank to the RO system. Securely tighten all the connections, but avoid applying too much pressure, which could lead to the breaking of plastic connections.
Step 9: Refill and flush
You are now at the end stage. Open the inlet valve and connect the system back. Allow the storage tank to fill. Depending on the water pressure, this may take some time. Once the tank is full, open the faucet again. You need to rinse the pipes. Keep running the water for around 10 to 15 minutes. This allows the remaining cleaning agents present in the filters or pipes to drain out. Keep tasting the water as needed. Once it tastes normal and fresh, your job is complete.
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Post-Cleaning Checks
Having made all that effort, you need to ensure everything is working properly. Don’t just walk away. Run some quick tests.
First, carry out a visual and taste test. Fill a glass with water. Hold it up to the light: it should be completely clear. There should be no particles floating in it. Take a small sip: it should taste fresh and neutral. If it tastes sour or soapy, you may need to clean the system again or give the tank an extra good clean.
Next, do a smell test. Have a sniff of the water in the glass. There should be no strong chemical smell at all. If you can smell chlorine or vinegar, there are still residues from the cleaning products present. Continue to run cold water from the tap until the smell goes away. If the smell persists after several flushes, you may have a problem with your filters rather than your tank. You may need to replace the sediment filter or activated carbon filter.
Check the water flow, too. Open the tap fully. The water should be coming out with good pressure. Low water pressure could indicate incorrect tank pressure. There should be a valve on the tank stem (the air valve). You can use it to adjust the air pressure using a pump—only if you are comfortable with it. Otherwise, look out for any leaks.
Finally, give the equipment a good clean. Look at check valves and joints where you attached the tank to make sure there are no drips. Tighten any loose parts carefully. Dry the area around the equipment to stop any mold growing outside.
Cleaning Variations for Different Tank Types
You may have a U-shaped storage tank or a cylindrical one. Cylindrical tanks are the most common type and stand vertically. U-shaped tanks are commonly seen in compact wall-mounted units. Although the cleaning process is similar for both types of tanks, U-shaped tanks can have sharp edges and corners, which can create areas for dirt to settle. You might need a soft-bristled bottle brush to thoroughly clean the various nooks and crannies.
You could be dealing with a stainless steel tank versus a plastic one. Plastic tanks are lightweight but tend to retain smells over time. Stainless steel tanks are strong and resistant to smells. However, it can develop rust if left to contain strong chemicals like bleach for too long.
If you have a stainless steel tank, limit yourself to white vinegar and mild soap for cleaning purposes. They are gentle on metal surfaces and effective against scale buildup.
Brands like Kent, Aquaguard, and Pureit come with specific user manuals. Some premium products have proprietary plastics, which may degrade when exposed to vinegar. They might recommend a tank cleaner. Also, cleaning such tanks with vinegar may cancel the product’s warranty. Please refer to the user manual to understand any manufacturer-specific cleaning recommendations or products required for your tank.
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Maintenance Tips Between Cleanings
Try a simple and quick method of cleaning—descale the tank regularly. Empty the tank completely every month and run the standard hose to drain it. This helps to remove stagnant water, which is the primary source of unpleasant smells. Allowing the tank to fill up with fresh water helps to create a flow of circulation throughout the system. Making it a part of your daily routine can make a big difference.
You need to keep a check on your filter and membrane replacement schedules. Although the tank is cleaned, if the filters are dirty, then the entire purpose of the system will be defeated. A sediment filter removes dust particles and sand. The activated carbon filter eliminates chlorine and unpleasant odors. Clogged filters can lead to bacteria being released back into the clean water tank. Clean them as per your schedule; generally, it should be done every 6-12 months. The RO membrane has a longer lifespan of 2-3 years. Maintain a record of when to change them.
Ensure good hygienic conditions around the purifier. Avoid keeping dirty plates and damp sponges nearby. Dust and moisture around the device can contaminate its external parts. Regularly wipe the water purification system’s outer body with a damp cloth.
Keeping a ‘date of last cleaning‘ note is a good idea. Use some waterproof adhesive tape to stick a note on the tank or any accessible part of the device indicating the date of last cleaning. Thus, you don’t need to depend on your memory to figure out when was the last time the tank was cleaned. It’s a simple way to keep yourself organized and ensure that the cleaning task is completed.
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Fix Common Problems
Even after proper cleaning, some issues may persist. Here’s how to deal with common problems.
If water tastes sour or metallic after cleaning, it implies that you have not rinsed well enough. The cleaning agent is still present in the system. Drain and fill up the tank again; ensure that you run the tap for a longer duration. If the metallic taste persists, the issue may be with the tank itself. Older steel tanks may develop internal rust. If the condition is severe, you may need to replace the storage tank.
What if you spot thick sludge or algae? Even after cleaning, algae can return within a few days, indicating a deeper issue. Algae could be entering through the supply line, or there could be excessive humidity in the area where the tank is placed. Clean and sanitize the entire water purification system with a strong disinfectant suggested by an expert. Additionally, check and replace the filters, as any fungus might be thriving in them.
Any leakage or cracks should lead to immediate cessation of using the appliance. A small leakage can lead to flooding rapidly. Begin by examining the connections—tightening them may help resolve the issue.
However, if the crack is on the tank, you cannot repair it and need to purchase a new one. Using a flawed water purifier puts you at risk of being contaminated with airborne pathogens and bacteria. If you suspect any leakage, it is advisable to seek help from a qualified technician.
Conclusion
You can keep your RO water tank clean at home. You don’t need any special skills to do this—just some patience and the right equipment. Follow this guide to ensure your family has access to good quality, 100% safe drinking water free from bad tastes or disease-causing bacteria.
Before starting the cleaning process, switch off the system and release any built-up pressure. Clean the device thoroughly to remove any stains left behind by the cleaning solution. Don’t wait for issues to arise—make cleaning of water purifiers a part of your household routine. A clean tank ensures good health and great-tasting water for all. Get the necessary accessories and take good care of your purifier.
Frequently Asked Questions (FAQs)
How often should I clean the RO water tank?
You should aim to clean it every 6 to 12 months. If you live in an area with hard water or notice any changes to the flavor or scent, then clean more often. Regularly draining the machine keeps it clean between deeper cleaning sessions.
Can I clean with household bleach?
A small amount of unscented bleach can be used to sanitize, but with caution. Bleach can ruin the rubber O-rings and the bladders that are part of the tank’s equipment. Many manufacturers advise against its use. White vinegar is a better option to clean your tank at home.
Is it safe to use vinegar with RO systems?
Yes. Vinegar is mild and effective at removing scale. Check your equipment manual, however, as some types of membranes or storage tanks may be damaged by acidic substances. If you are unsure, use hot water and a mild detergent.
How long does it take to clean the water tank?
Cleaning the entire water tank typically takes around 45 minutes to one hour. This includes draining the tank, scrubbing it clean, rinsing it, and allowing the tank to fill back up again. Taking good care of your water equipment requires just a little bit of effort.