yeah i know theres a lot to consider,ive been through everything i can think of,the nutrient i use is ionic,with boost applied,so there really should be no defficiancy,ive always used this,my previous growroom had slightly different dimentions and it was spot on,yielding around 6 to 7 oz a plant,im down to around 4 a plant ands thats quite a significant drop,thats why i think its an atmosphere thing rather than a nutrient prob.