Adding more light at flower

[BG Bud]

I'm considering adding another light source for flowering in my 3x3 tent. I have a 1200 watt King LED . Plants under scrog and have been topped and trained . Perhaps too much ?? Pic below. Temps are great and avg. 74 with lights on and 67 with lights off. I am at 18/6 and hoping to flip in 2 weeks or sooner. They look like Indicas and are all female. Concerned another light will increase heat too much. My light does not have a veg/flower switch. My first grow so sucking up all the info this wonderful sight keeps offering. Appreciate any and all input . How do the plants look to you ?Thank you

 

[BG Bud]

Sorry the above is at 6 weeks of veg