IMO 5 or 6 inches away is to close for a 250 watt mh bulb. I use two 125 watt HIDS and I keep them about 12 inches away during the entire grow. Also, make sure you don't splash any water on the leaves of your plant as your watering, it water will magnify the light and burn the leaf very quickly. This is why I do not recommend foliar feed (spraying) for plants, unless you do it at the start of the dark cycle during 18/6 vegging, and never in flowering.