TDS (Total Dissolved Solids)
Measures the total amount of dissolved substances in water—like minerals, salts, and some organic matter—usually expressed in ppm (parts per million).
Commonly measured with a TDS meter or derived from EC (electrical conductivity).
But TDS doesn’t indicate what specific minerals are present, and crucially, it doesn’t reflect the presence of hardness-causing minerals.
Hardness (as CaCO₃)
Indicates the concentration of calcium and magnesium ions in water—also shown in ppm or mg/L.
These minerals are responsible for scale build-up, soap scum, and household appliance damage.
Hard water can hurt appliances, reduce soap efficiency, and leave residue on dishes.
Why the Distinction Matters
A TDS meter might give you a general idea of total mineral content, but it’s not accurate for measuring hardness.
Water softeners specifically target calcium and magnesium (hardness) — they don’t necessarily reduce overall dissolved solids.
Checking only TDS can mislead consumers: A softener might leave you with low hardness but unchanged or even higher TDS, leading to confusion.
Wavoo Hard Water Softener: Your Solution for Genuine Softness
Here’s how the Wavoo Hard Water Softener stands out:

Why It Matters
Reduces Ca²⁺ & Mg²⁺ (Hardness Ions): It targets scale-causing minerals so you enjoy soft water, reduces limescale, and protects your appliances.
Doesn’t Reduce TDS: Because it doesn’t demineralize water entirely, TDS stays steady—so don’t rely on TDS readings to judge performance.
Built for Domestic Use: Compact, user-friendly, and effective for households dealing with hard water issues.
Clear Communication: Emphasize “Reduces Hardness, Not TDS” on your Amazon page to avoid confusion.
How to Test for Hardness (Not TDS)
Instead of measuring TDS, consider:
- Hardness Test Strips: Quick, easy, and inexpensive for household use.
- Drop Test Kits: More accurate—ideal for placing before and after softener.
- Professional Lab Meters: Accurate but typically for lab or industrial users.