If you have a water filter at home, you may notice that water leaks after using it for sometime. The culprit is most likely the O-ring. An O-ring is a rubber or elastomer seal. You’ve probably read that an O-ring failure caused the destruction of the space shutter Challenger. Well, it is similar thing.
O-rings are quite cheap for household use. The ones for water filters should cost around RM 5.00 each. At this price, it is considered expensive already. There are places that sells O-rings for even much higher prices. I do not know if it is because the specification is for different grade but some cost as much as the entire 2 stage water filter itself.
Anyhow, if you are looking for replacement o ring for your water filter, try your local hardware shop or larger modern hardware shop in malls.
Another possible reason why water leaks happen is the lubricant on the O-ring dries after some time. As a result, when you tighten the filter housing, friction causes the O ring goes out of shape. It no longer retains its O cross section and water pressure caused leaks.
What you can do is to tighten the water filter housing then reverse the tightening by unscrewing the filter housing slightly. Then screw it again and slightly reverse until it is finally tight enough. This way, the O ring maintains it shape and prevents water from leaking out. Try it the next time.