Parts per million (PPM) is a way of expressing percent (%) in small amounts. In hydroponics or soil, it is used to express the quantity of one amount of material dissolved into another (salts into a volume of water). Most plants do well between 1000 and 2000 PPM. It's also used for Co2 rating, regular atmosphere is around 300 PPM but with Co2 you want a range around 1200 - 1500. Depending on if your using clones or from seeds? that will determine the veg period. like us, these plants like the same temps we like around 75 degrees, try to keep temp changes within 10 degrees so you don't shock your plants... good luck