So, if I'm understanding things correctly, you have 3 x 315w CMH over 3 plants in large fabric pots?
Do you think the plants are leafier because of the CMH? I've heard, they produce buds that resemble more closely outdoor flowers - which I've always just interpreted to mean "leafier". The other question, how far away are your lights from your tops? How big is the footprint the lights are covering? (Bubba can produce leafier plants in her offspring, worth of note.)
I'm playing with 2 x 315 in 2.5' x 5' - that puts me at 50.4w per sq ft - which is generally considered the necessary statistic to meet - even though, that is the old way and PAR is more important, blah, blah.
Everyone used to run the basic 3x3=400w 4x4=600w 5x5=1000w - I used ran a 400w in a 2x2. It produced much higher quality in the refined space at 100w per sq ft. Flowers weren't too much different than those produced under a 1k.
I'm hoping, the new technology hype is true with the CMH. Everyone was again saying 3x3 per lamp, but that just seemed too big, knowing what I know about 400w'ers, I went a bit smaller, to still meet the old metric.
I've had the lights, every where from 22" to 10-11" away from the tops of the plants. Sweet spot for me seems to be about 14" away from the tops. Even then, canopy penetration is only about 12-15" deep. I wouldn't waste time with anything below 16". I've stripped a bit over 3' of my plants bare for canopy management. The grow would be a waste of the plants energy as enough light just doesn't get there.
Not sure how long you've been running CMH, but there is certainly a learning curve with them. I'll know more what I think about them after the first harvest under them.
We'll find you something better to smoke.