Get your water tested so you know what you need to filter in the first place. I've had filters for acidic water, iron in water, and hard water. Hard water just needed a salt tank, the rest used their own back flushable systems that last practically forever.

I use pure it

Alta Water altawater.com

I love mine. Cleans out all the junk, mineralizes and structures all in one system.

i have an aqua-pure system at the utility level. two big boi filters for the whole house. nothing to compare it to but it’s been great!