Buy a cheap TDS meter for $10–15. Test your tap water, then test your bottled water, then test your neighbor’s (they’ll think you’re a science genius). It’s a party trick that actually teaches you something about your local geology.
If you’re using a filter, test before and after. A Brita pitcher typically reduces TDS by 20–30%, while an RO system can drop it to near zero. For daily drinking, 50–150 ppm is lovely—it feels crisp but not stripped.
Pro tip for travelers: check the TDS of tap water in a new city before you drink. If it’s above 600 ppm, consider bottled water for a few days until your gut adjusts. Your stomach will thank you for the data.
What Is TDS in Water and What Does it Indicate?
The Fun Fact Zone
Did you know that the Dead Sea has a TDS of 330,000 ppm? That’s why you float—but don’t drink it. In contrast, rainwater is usually below 10 ppm. The range of how we define “water” is wild.
In Japan, some people pay premium prices for water with a specific TDS from local mountains. It’s like the hipster vinyl of hydration. Meanwhile, in parts of India, high TDS is common and accepted as normal—different geology, different norms.
Even your body has a TDS equivalent: human blood plasma runs around 9,000 ppm of dissolved solids. You are basically walking around as a very salty bag of water. No wonder we crave balance.
