Is a whole-home RO or drinking-water filter worth it in Dubai, or is the tap water fine?

Straight answer: Dubai tap water is treated and safe to drink — so this is a taste, scale and preference decision, not a safety one. That means you almost never need a whole-home RO. Match the system to the actual problem: a softener for whole-house scale, an under-sink RO for better-tasting drinking water at the kitchen tap, and a simple sediment/carbon filter if you just want to knock back taste and particles.

What each one does: - Softener: treats hardness across the whole house — protects the water heater, taps and appliances from scale (this is the one that stops limescale wrecking things). It does NOT make water taste better or 'purer'; see the is-a-softener-worth-it thread. - Under-sink RO: strips almost everything for clean, better-tasting drinking/cooking water at ONE tap. This is what replaces your bottled water. Sensible and cheap to run. - Whole-home RO: RO for the entire house — expensive, wasteful (rejects a lot of water), and overkill when the water's already safe. Rarely worth it in a normal home.

So for most homes: an under-sink RO for drinking + a softener if scale is your enemy. Whole-home RO is the wrong tool unless you have a very specific reason. And no, it's not really DIY — an under-sink RO needs a correct feed, a drain connection for the reject water, and the pressure right, so get it fitted by a plumber in Dubai who'll set the drain and check pressure rather than leaving you a slow drip under the sink.