i have (2) 400w mh and (6) 40wfloro vertical.a fan on them. and an ac vent above blowing down on everything(set at 73f)have had a problem with Mn toxicity due to tape water.epsom saltwater fix. use rain water now.everything is doing ok now. figured start co2 for 4 wks then flower.let me know what ya think.oh yeah my girls are pretty old (3 mos) not real tall but healthy for plants under floro only for 2 months but now we are cooking with Mh baby.