MILLIARD 400W Grow Light Ballast Kit Great start to building any indoor greenhouse. Designed for use in the MILLIARD Hydroponic Grow Tent and our full line of MILLIARD propagation products. Each bulb gives off a different hue of light. HPS bulbs give off a brilliant yellow light for plants that grow best in low or indirect light. MH bulbs throw bright white light in a wide spectrum suitable for most other plants. The 400W ballast is variable-output for dimming your lighting rig to suit plants with particular needs. Includes one HPS bulb, one MH bulb, a variable output ballast, a 19