I use bottled water or brita filtered. The PPM of these is between 80 and 200ppm (not good huh?).
Do PPM calculations include the source water? Like should I subtract that number first?
Also I have a 600W LED - have far should I keep it from my clones / seedlings (they are about a week and are doing good I just dont want to ruin them). Does anyone have chart or something that shows how close the light should be throughout the grow, by wattage?
Thanks this forum is great.