How often should I change my drinking filters?

One question that we’re always asked is “how often should the drinking filters be changed?”

reverse osmosis drinking system bayfield huron waterIf we’re talking about a reverse osmosis system, the general rule-of-thumb is annually. This would be based on a family of anywhere from 2 to 6 people and assuming that the water entering the filters is free of hardness and iron.

If there’s only 1 person using the water, the filters don’t have to work as hard. In this case, less frequent maintenance perhaps every 2 years (to test the water, change the filters and flush the system) is often OK.

With a large family, or in areas where the incoming water is a problem, maintenance may need to be every 6 months. Because so much water is going through the filters – if it’s left for any longer – the production slows down to almost nothing and they run out of purified water.

Each situation is slightly different and we can customize our service to fit each individual need.

“But I don’t want to drink softened water”

Unless you have a single carbon filter cartridge on the kitchen cold line (in which case you want it to be hard water), the reverse osmosis drinking systems should have softened water feeding into them.


Regardless of whether hard or soft water is fed into them, the water that comes out the faucet is completely free of any dissolved solids. No calcium. No sodium. It’s not hard or soft – It’s simply purified water.

But it’s easier for the system to remove the sodium from the softened water than to have to deal with the calcium that’s in hard water. If you examine your kettle, you see the buildup of hardness on it, then you understand how the RO membrane will look after time on hard water.  The softened water doesn’t stick as bad so the system doesn’t get as scaled up.

The part of the system that the prefilters is protecting is called the membrane. There are many different membranes available on the market today.  The membrane must be matched to the water and the system to work properly and effectively.  This is where we come in matching the system to specific need and water supplies.