High Intensity Discharge (H.I.D.) Grow Lights
You are going to need an HID lamp to accompany your hydrosun ballast and complete your lighting. Metal Halide and High Pressure Sodium are two different types used for growing.
Metal halide lights were created to provide a spectrum as close as possible to that of the natural sunlight. This coupled with their intensity and energy efficiency, makes them ideal for indoor gardening. The bulbs range in size from 100 watt to 1000 watt with 400 watt and 1000 watt most popular.
An abundance of blue light emitted by metal halide makes them the best light for propagation and vegetative growth, promoting short internodal length.
High Pressure Sodium lights do not emit as broad a spectrum as Metal Halides lights, but have many advantages, especially when used in conjunction with halide. Sodiums last longer, and burn brighter, but are still more energy efficient. More yellow/red colour in the spectrum and less blue promotes a higher flower-to-leaf ratio in flowering plants. H.P.S. lights are widely used in commercial greenhouses, where natural sunlight provides sufficient blue. A combination of the two lights provides the best balanced for indoor grow room, especially when used with a light mover. 430 Watt Son Agro H.P.S. bulbs which supply 30 extra watts than regular ones are now available. This extra light in the blue end of the spectrum is great news for indoor growers. If you are planning a "single lamp" grow room, you can still get the benefits of both halide and sodium light. High pressure sodium "conversion bulbs", specially made to operate with M.H. ballasts, and is available in 400 watt and 1000 watt models. The bulbs can easily be interchanged as needed, using the same ballast and fixture. The size of the light needed will depend on the size of the growing area and the type of plants you wish to grow.