Quote Originally Posted by macnasty
sorry herbie but i'm still confused. 1500 ppm is NOT a measure of volume, it's a ratio, right? do you mean to say that the schedule implies that the plant only needs 1 gallon at 1500 ppm per week? or am i still way off? thanks in advance.
You are correct, PPM is parts per million. This has nothing to do with any one-week interval, it is the level of concentration for a given stage of life, and a plant in full bloom sucks down nutrients a lot faster than one in early veg.