Any more tips to get the best results?

Question from a fellow grower:

Hi, Well I am at 10 weeks on 18 White Widow Fem plants. Most are between
28" - 36". I am turning and moving plants regularly. Now I have
separated ( plants and turning lights to 12 hours. After reading your
guide , I am adding 3oz of wood ash to soil of each plant. This will
draw into plant as I water daily. I have ordered a 50# Co2 can. Will a
half pound of Co2 twice a day injected into room be enough ??? I have
never used gas before! My budding lights are fixed @ 6’ 2 - 600 watt 1- M
H & 1 - HPS they will be on super mode… What am I missing. I am
Holding the other 9 plants till 4 months.I figure the might get to 5’
prior to budding.Also I have prune a couple of the plants and I have
messaged a couple too experiment. What else can I do to get best

Plants will need 1500 ppm of co2 for good results. Wood ash ? never heard of that - learn some thing every day – thanks !