Welcome to GWE
Thats only 10 watts per plant, I have a single plant (Greasy Grapes) under a mars hydro tsw 2000 (~308 watts), it takes up the entire 3x3 foot print of the light. I agree with you you need more light.
I also agree that everything maters, pot size, whats in the pot, feeding, watering, temps, RH, everything!