I know this is necroing, but i've had one of "the perfect water" systems going on 2 years. The under the sink system can have UV light to reduce potential bacteria. Its reverse osmosis and multi stage, with a mineral stage. It has a staging tank thats pressurized so you get decent flow for like 3 gallons of water or something like that. It can have an attachment to go to your fridge even.

Literally the best water I've ever had, I'd never go back.

Changing filters is a little annoying, but you do it once a year and it took me all of 10 minutes. The reverse osmosis filter is every 2 years. You only ever put bleach on the tanks nipple like once a year and less than a spoon full. The longest part was draining and refilling the tank like 3 times to get the filters and tank primed after filter change.

They do whole house filters too.

https://www.theperfectwater.com/all-products

Whole house filter or a multi–stage filter

reverse osmosis. try Ecosoft. it's a Ukrainian brand.

I don't know if these filters for permanent installation have some techology to prevent this, but the smaller jug-style water filters increase bacteria growth if you don't regularly exchange them. I think for a part with such a huge internal surface that is permanently wet, this is really hard to avoid unless it has a special desinfection mechanism.

https://www.businessinsider.com/water-filter-mistakes-increase-risk-bacterial-infection-2021-8

For short-term use while hiking I use water filters by Sawyer or Katadyn so far without problems. But I rinse them with chlorine and vinegar before I put them away for storage.

APEC water systems. Multi stage.