Sarge, you should go to home depot or lowes and purchase a couple sheets of stirofoam insulation and build a makeshift wall to help enclose your light around your plants. You are losing a lot of light into the room and it is not being directed towards the plant..... In other words, You are losing "Lumens"

Your plants would greatly benifit even if you were to spray paint a couple pieces of large cardborad flat white and use those as temporary walls... Anything to help reflect as much light back to the plants as possible.:jointsmile: