Im a bit confused on how ppm work with nutes and water. I know you use a tool to measure ppm but what exactly are you trying to accomplish weekly during feed. How do you adjust the ppm up or down and so on. Following the chart that came with the nutes is kinda confusing. For example, if plain water was at 400ppm and the chart says 900ppm with the nutes and i put the correct ppm in and it goes to 800ppm am i suppose to add water or subtract water or add more nutes? Can some one break down on how PPM is used/adjusted with water? Thanks