Countertop models are the lazy person’s dream—just screw onto your faucet and go. Under-sink units need a bit more DIY love, usually involving a drill and some patience. Pro tip: If you’re renting, stick with a countertop version. No need to negotiate with your landlord over a hole in the granite.
Fun fact: Some systems have a UV light stage that zaps any lingering viruses. It’s like giving your water a sunbath—but in a very sci-fi, plumbing sort of way.
