so i have 2 plants at 19 days old in coco under 1 600 hps they are growing at a rate of just over an inch per day, is this good or bad, how can i increase their growth rate. i have fresh air intake filtered fan drawing it out and a fan for wind. the temp is 27 c dropping to 23-25 c when the light is off, they are 20 inch high now i want to get them about 4 ft before flowering