First, the countertop models are your budget-friendly heroes. These little guys sit on your kitchen bench and hook up to your faucet. You can snag a decent one for $150 to $300. They’re perfect for renters or people who hate drilling holes in their granite countertops. (No judgment—granite is expensive.)
Next up: under-sink systems. These are the most popular because they hide away like a ninja. Prices range from $200 to $600. You’ll get more filtration stages—usually four or five—which means your water goes through more “checkpoints” than a celebrity at an airport.
Then there’s the whole-house RO system. This beast filters water for every tap, shower, and toilet in your home. Brace yourself: costs start at $1,000 and can skyrocket to $4,000 or more. It’s overkill for most people, but if you’re a water snob with a six-figure income, go for it. Your plants will thank you.
