Parts Per Million (PPM) parts per million (ppm) Parts Per Million (PPM) is a unit of measurement to determine how many Total Dissolved Solids (TDS) are in the water you feed your plants. It is a way to assess how many nutrients are in the water.Testing PPM and EC Related Terms EC / TDS / pH level << Back to Glossary Related Posts:Man Charged with Over $3 million Worth of Cannabis…Man Charged in NSW Over $6 Million Worth of Cannabis…Colorado Produced Nearly $2.2 Billion Worth of…Total Dissolved Solids (TDS)Oregon State University Receives $10 Million for Hemp MarketDog Sniffs Out £1 Million Worth of Cannabis Plants