I have a 4 600w air-cooled set up with about 30 plants flowering at a time. I can't be moving the lights up and down or else I can't move around the room and manage the ducts, so the lights are stationary. Right now I have the plants on pallets resting on cinderblocks, but they are still not close enough to the light. What is the easiest way to raise and then lower the plants as they grow?