When to Change RO Membrane & Filters?
If you are using an RO water purifier then you know the importance of changing the RO membrane and filters on time.
Timely replacement of RO filters and membranes is very important for ensuring 100% pure and safe drinking water.
When we talk about the maintenance of RO purifiers the first thing that comes to our minds is the replacement of the filters and membranes.
You must have a basic understanding of the periodic schedule of replacement of filters because filters and Membranes constitute the major parts of any water purifier. The cost of replacement of filters and membrane is around 80% of the total maintenance costs of an RO purifier.
The purpose of this post is not to turn you into a technical expert on RO water purifiers but to give you a fair understanding of when to replace the filters and membrane of your water purifier.
This information helps in –
- making sure that you always get clean, pure, and 100% safe water.
- increasing the life of your RO water purifier.
- reducing the maintenance cost.
- avoid being cheated by unethical service technicians.
The question at hand may seem to be very clear and quite straightforward but the answer is not so simple because when we talk about replacing the filter and membrane the approach can’t be ‘one size that fits all’.
Therefore, before we start spilling the beans on when to replace the RO membrane and filters, it is important that we first tell you about all the factors on which it all depends.
The below factors should always be taken into account before estimating the good time to change the RO membrane or filters.
- Level of impurities in the input water.
- TDS Level or hardness of the input water.
- How much water do you purify using your RO purifier?
If the water has a very high level of impurities, a high TDS level, or if you use your RO purifier to purify large quantities of water, then the filters and RO membrane would need to be replaced quite frequently.
The schedule of change of RO membrane and filters that we have put out in the following paragraphs is for an average Indian household of around 4-6 family members.
The RO pre-filter (installed outside the RO water purifier) should ideally be replaced every 3 – 4 months. The replacement interval can be shorter or longer depending upon the quality and quantity of water purified.
The other filters which include the Sediment Filter and Carbon Filter should be changed every 6-12 months depending on how much water you purify and how good or bad the input water is. However, this is just an average and to get the exact time to change them we need to look at filters individually.
When to Change Sediment Filter?
A sediment filter is designed to remove sediment and dirt from the water so your carbon filter and RO membrane don’t get clogged prematurely.
Every home might have a different amount of sediment in the input water so there is no ‘one size fits all’ answer to tell you how long it should last for you.
It is important to keep the pressure as high as possible going into the membrane and the sediment filter would only cost a few hundred rupees so it is always recommended to change the Sediment Filter on time. If the Sediment filter is not changed on time then the dirt will reach the RO membrane and the membrane will get clogged, this reduces the efficiency and the life of the RO Membrane.
If you maintain your Sediment Filter properly, the Carbon Filter and RO Membrane should last longer.
We recommend that Sediment Filter should be changed at least once a year.
When to Change Carbon Filter?
Water from the Sediment Filter is passed through the carbon filter (also known as the Activated Carbon Filter), which removes chlorine and other organic contaminants. A carbon filter also filters out the bad odor and unpleasant taste of the water.
Chlorine in water also adversely affects the life of the RO membrane. An activated carbon filter absorbs Chlorine and other organic impurities and thereby extends the life of the RO membrane. It is therefore very important to change the Carbon filter at regular intervals to increase the life of the RO Membrane and prevent bad odor and bad taste in the purified water.
We recommend replacing your Carbon filter at least once a year.
When to Change RO Membrane?
The RO Membrane is the most vital part of any RO water purifier. RO Membrane is the filter that is doing all the work, the Sediment Filter and Carbon Filter are only preparing the water for the RO membrane so it doesn’t get damaged.
Learn more about how RO technology works to purify water.
If you take good care of the sediment and carbon filters and replace them at the required intervals then the RO membrane only needs to be changed after purification of 4,000 to 6,000 litres of water.
The RO membrane may die early or last longer depending on the TDS of input water. The replacement of the RO membrane will be based on the consumption of water, quality of input water, and efficiency of the sediment filter and carbon filter.
2. Rejected water flow increases.
Typically, RO Membranes last for about 2-3 years, however, we have seen them go as long as 4-5 years. Your RO membrane may die earlier if you have really hard water or if you never flush the membrane.
The best way to know when you should replace your RO membrane is to check the TDS level of purified water. You will need a TDS meter like this one to find out the TDS level. If you don’t already have one, we recommend buying a digital TDS meter to easily find out the TDS in water.
YouTube Video: How to Check TDS Level of Water at Home
You will know that your RO membrane is starting to go bad when the TDS begins to climb. This can often happen pretty suddenly because of that we recommend changing the RO membrane every 2-3 years.
Please Note: If the input water is very hard or has a high TDS then the RO membrane may need to be replaced more frequently. You should always check the specification of your RO purifier or most accurately that of your RO membrane. For example, if the RO membrane is capable of purifying up to 1500 ppm of TDS, purifying input water that has higher than 1500 ppm of TDS will reduce its life.
We all know RO water purifiers are quite expensive as compared to other types of water purifiers but an absolute necessity to purify high TDS water. The cost of maintenance or AMC of RO purifiers is also comparatively high because of costly filters and membranes.
Apart from the cost, we also know that RO purifiers result in huge wastage of water as an average RO water purifier produces around 70-80% of wastewater.
If you are also using an RO water purifier and concerned about the amount of water being wasted then you may consider reading about our Top 6 Innovative Ways You Can Use the Waste Water from RO Water Purifiers.
You should use an RO purifier only when the input water has high TDS (over 500 ppm) and the water doesn’t taste natural.
If the water supply at your home does not meet the above criteria then the initial cost, cost of maintenance, and wastage of water in an RO purifier will overshadow the benefits.
For effective purification of low TDS water, you can opt for a multi-stage UV purifier, which costs less, maintenance cost is less, and wastes negligible water. The best part is, that UV or UV+UF water purifiers do not produce any wastewater like RO purifiers and hence you can save a lot of water.
Livpure service is even worst. They have installed the purifier on a monthly subscription payment basis. They have not serviced the water purifier even after 3 years of use. Don’t know whether the output water is pure or contaminated without any change or replacement of filters.
Very useful Sir. Thank you so much for the excellent analysis.
What’s the problem if you change sediment and carbon filter and the waste pipe doesn’t stop water even if the tank is full
The auto-shutoff mechanism is not working as it should. You need to get this checked from a service engineer.
I am not satisfied to use the kent RO filter. I paid 20000 rupees to buy one in Oct 2018. Now after only 14 months RO system can not store pure water. Technician says membrane failed now. How can membrane fail in just 14 months? They say total expenses will be Rs. 3100. I think its too much. Every year near about 18 % cost. It’s not right.
Yes and worst service ever
Very useful.
Step by step details of every stage of domestic water filter.
Very useful information. I have come to know a lot reading this article.
Good information
Excellent…and well demonstrated.
Your article is fine describing the working of RO system. But it will be better if you write at what TDS level we have to change the RO membrane.
Thank you for sharing such detailed and very useful information. This will definitely be helpful for people who are using RO purifiers and often remain confused about when to change RO membrane or filters.
Thanks for the information about the water purifier. I bought Eureka Forbes Aquagaurd RO UV 3 years ago. It’s excellent, today service person said that the TDS level is just increased but I used to change the pre-filter every year. So I am going to change the membrane. I am proud of Eureka Forbes.