Before you buy, check for waste water. Yes, RO systems send some water down the drain (it’s how they remove contaminants). But modern ones are efficient—look for a 1:1 ratio (one cup wasted for every cup of clean water). It’s not perfect, but it’s way better than the old 4:1 water wasters.
Also, mineral retention. Some people worry that RO strips out good minerals. Truth? It does remove some, but you get plenty from food. And there are alkaline remineralization filters you can add if you miss those minerals. It’s like putting sprinkles on your already-delicious water cake.
Finally, installation difficulty. Most under sink systems are DIY-friendly. You’ll need a drill for the faucet hole (if you don’t have one already), but it’s not brain surgery. If you can assemble IKEA furniture without crying, you can install an RO system. And if you can’t, hire a plumber—it’s worth the peace of mind.
