Thanks for the lamp distance info.Well if it is your second grow I think you might be ok running coco. Just remember it has NO nutrient value. Also water when the top of the coco turns a light brown. I would grab a 2.2lb bag of maxi bloom from your local hydro store (about 20 bucks) Drip Clean from House and garden and some canna coco. The canna coco is 20 bucks a bag, but its the best coco hands down. You will need two bags for six, three gallon containers. In coco bigger pots are not necessary, you want to be watering the coco everyday if possible and 5 gallon pots stay saturated too long for plants under 4 ft IME. If you have a fan under the bulb you could get as close as 12" which is where one of my anesthesia's is at. I do not reccomend this and I think 30" from the main stem is best.
Any other substitute for chunky perlite?
Just to confirm nutes: Maxi-Bloom, Green Planets Massive, hygrozyme, cal mag, and Amino Aide. Do you have a brand suggestion on cal mag and Amino Aide, as well as amounts? Thank you.
Ventilation and temps will be my challenge. Had a larger tent before and have a Can 50 Combo which at first glance is a bit much, yet with a speed controller might do the trick. http://htgsupply.com/Product-Can-50-Combo.asp
Wonder if you might provide a vid or pics showing off your set-up, along with vent, intake, outflow, and what fans you're using?
Thanks, again.