i have a couple of plants that are in there 3rd week of vegitation. i went out and purchased a trimeter to measure tds, ph, temp. what should the tds be at for this stage of growth. I keep hearing about 800ppm. i am around 190ppm. Is it that much through the entire life of the plant or should it differ by week. I would think that it would differ by how heavy the nute solution was concentrated. also does anyone have a chart or anything that might say what it should be at any given time. any help anyone has would be greatly appriciated.