Check the filter lifespan for your particular RO system in the user manual.
I also recommend buying a TDS meter. It’s the best way to monitor filter life.
Take a reading after you install the system and then every month after. When the TDS readings start to go up, it’s time to replace the filters.
The Importance of Replacing Filters on Time
It’s better to replace the filters too early than to do it too late.
Delaying filter replacement reduces the quality of your drinking water and reduces the durability of the entire system.
As the filters clog and age, they’ll start to allow more and more impurities through.
These contaminants include suspended particles that clog the RO membrane and chemicals like chlorine that damage it.
Over time, your RO membrane will start failing as well, letting through bacteria and other impurities.
This puts you and your family at risk.
That’s why I highly recommend a TDS meter.
Buying the Right Replacement Filters
Buy the replacement filters well ahead of time or when you are ordering the RO system.
This ensures you have spare filters on hand in case the company goes out of business or for some reason, and you can’t order new filters.
Most RO system manufacturers sell spare filters in sets. You can get a set of all the filters or a complete set containing the filters and the RO membrane.
If you are replacing the membrane, you can usually buy it separately.
Make sure you buy the right filters. Check the manual for the name and model of the manufacturer-recommended replacement set.
When you are buying the replacement, also check which RO models they are compatible with. If you are not sure, contact customer support.
Finally, you should only buy replacement filters from the manufacturer or an authorized reseller.
Replacing the Filters
The following are general guidelines. The specific filter replacement process differs slightly for each RO system.
Read the user manual for specific instructions that apply to your system.
Generally, you don’t need any tools to replace filters. But some RO systems come with a wrench that you can use to loosen the filter housings.
Replacing the RO membrane
Most RO membranes need to be replaced every 2-3 years (3-5 years for Home Master systems).
To replace the membrane, start with the above steps up to where you wash your hands (turn off the water, turn off reserve tank valve and ice maker valve if applicable and relieve pressure by opening faucet).
Replacing the Post Filter
The in-line carbon post filter is replaced every 6-12 months. In most cases, you replace it along with the pre-filters.
Again, follow the initial steps outlined above.