What is the difference between ppm and mg/L?

Parts per million TDS or ppm (abbreviated) is an expression of quantity, mg/L (milligrams per liter) is an expression of weight. Both are used as scales
for TDS, but ppm is more popular. There is no conversion factor since 1 ppm = 1 mg/L.

Learn more:

• Blog – Meeting Environmental Standards for TDS in Wastewater Treatment
• Technical Article – Total Dissolved Solids Measurement