Im using a 250 watt metal halide at the moment but can any body give me some guide lines on how close to to my plants it should be for best results in vegging Regards Smelly
Hold your hand under the light. Put it in a place that feels warm, but not hot at all, and hold your hand there for 1 minute. If the back of your hand stays warm without getting hotter then you've found how close you can put your light. My guess is somewhere around 8" to 10". Around 20" from the bulb there aren't enough lumens to grow with so your "green" area is probably between 10" for the bulb to 20" from the bulb. Begin flowering your plants when they are around 6" tall, or use a scrog method, for maximum efficiency.