I use a 10” 3 stage system. First a 20 micron filter, then a 5 micron filter, with the last stage being a carbon filter with a nominal 0.5 micron rating. This feeds a dedicated tap on the kitchen sink and the ice maker in the fridge.
Depending on usage levels, I change them all every 2-4 months. About 800 gallons, I think. Nota bene: This is a larger than average system, on a par with an undersink reverse osmosis system.
I can drink my tap water straight from the faucet, but it tastes better filtered, as does the ice. I use the filtered water for cooking, as well as for the pets.
Thanks Don.