I just picked up a new 1000w hps light. It is a digital lumatek with the dimmable option. My grow room is 3x5x7. Is using the 1000w setting worth the extra heat? Or should I turn it down to 750 or even 600? I have the light about two feet from the tops. When I first switched from my old 400w to the 1000w I burnt the tops of four buds. That was a hard learned lesson. Thanks.