While the plants were small had them about 60 inches under my Covert Pro 630 @ 250W. They seem to be stretching a bit, so two days ago I bumped up the light to 380W. Plants responded well. The leaves all perked up and all three strains seem to like the added lumens. Today I gave them all a good watering with distilled water and cal-mag plus (6.5 PH @ 5ml/gal) and bumped the light up to 500W. Runoff was at 6.5 PH and 1450 PPM give or take, all plants were close to these numbers. Also, the pots seemed a bit light after watering so I watered each plant again directly into the run-off tray. The plants sucked up all that water within an hour and seem good to go.