Light height

I have a 400-watt high pressure sodium (HPS) hortilux unit with glass cover and air vents. I’m providing good air exchange. Can I lower the light to 12 inches from the top of my plants?

Yes. The temperature below the light will not be too hot. High heat at the plant canopy level makes the buds run. Air-cooled lights remove most of the heat so that the air near the light remains much cooler. A 400-watt HPS lamp can be kept 12 inches from the top of the plants.

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