fluctuating temps also play parts in vegetable matter growth and inter-node spacing, try to stay within 10deg day/night, and lower temps create compact inter-nodal spacing, use to use 1000 hid mh went to t5 for veg promotes short inter-nodal spacing along with cooler temps its like using bushmaster.
other is the foot print of your hood to consider the bigger and broader the better the foot print and even canopy light. i use para on 50in centers in 20x20x8