This varies widely. My SubZero fridge filter, for instance, costs $55, and is rated for 750 gallons or 1 year, whichever comes first: https://www.subzero-wolf.com/assistance ... ion-system
I know you keep repeating the same thing, which doesn't make it true. Here are scientific, peer review papers regarding the risks associated with reverse osmosis:Health concerns? Well, your $55 carbon filter will not filter arsenic, calcium, or salt. It will not eliminate ALL heavy metals like lead that are extremely harmful to the human body.
There's more out there.
Right, and remineralized water comes with its own risks. See the second article above.Again, if you are worried about the demineralization issue get the cartridge to re-mineralize the water.