Think of water as a party host. It picks up guests wherever it goes—dissolving bits of calcium, magnesium, sodium, and potassium from rocks and soil. These are good guys, the ones that make your water taste alive and crisp. But sometimes, the guest list gets a little wild with heavy metals, pesticides, or old pipe rust—those are the party crashers you want to keep out.
TDS is measured in parts per million (ppm). Zero ppm means absolutely pure water—which is actually boring and flat, like drinking a cloud. Meanwhile, a high number, say 500 ppm, can taste salty or metallic, like licking a penny that’s been soaking in a salt shaker. It’s all about the balance.