the plants are maybe 3.5-4ft tall. should i fim these guys, they are getting quite big.

during flower i can give the 3 plants the 400hps from the top, plus add a vertical flowering 12000lumen 250W CFL in the centre, so i don't think light is an issue for the lower leaves if the plant is tall. i'm more concerned about the plant spending too much energy on getting nutrients up and down...