From a fellow grower:
Do florescent lights help the growth when used along with a 400watt HPS, (of course I used a Metal halide to flowering stage) here’s a couple pic’s…
is that one plant? or several side lighting is supposed to add to yield by 10-15% but lowering your light closer to your canopy definetly would be a good start too
I had a very similar set up for a long time except I had a double four footer light on the back wall that I could raise and lower to go along with the plants growth
Eventually swapped the fluorescent out for a permanently mounted 80w HPS at about 18 inches high