I like using the GH 3 part and the rapid start during propagation and early veg, as soon as they show roots in the 1 gal pots I start them on the 5 part and they just eat it up, even at 1400 and 1500 PPM in mid bloom and I never saw any sign of nutrient burn or over fertilized. My next round will be a complete room of 8 Ball that Ive started from seed, thanks Barneys Farm. I worked it out and I ended up with just over 4 lbs for 4.5 600 watt HPS 0.66 gram per watt of light. The Zombie ended finishing up pretty nice and I will grow again in the future.