High-pressure sodium (HPS) lamps are smaller and contain additional elements such as mercury, and produce a dark pink glow when first struck, and an intense pinkish orange light when warmed. Some bulbs also briefly produce a pure to bluish white light in between if the mercury achieves its high pressure arc discharge characteristic before the sodium is completely warmed. The sodium D-line is the main source of light from the HPS lamp, and it is extremely pressure broadened by the high sodium pressures in the lamp. On account of this broadening and the emissions from mercury, more colors can be distinguished compared to a low-pressure sodium lamp. This leads them to be used in areas where improved color rendering is important, or desired. Thus, its new model name SON is the variant for "sun" (a name used primarily in Europe and the UK). HPS Lamps are favored by indoor gardeners for general growing because of the wide color-temperature spectrum produced and the relatively efficient cost of running the lights. Because of the extremely high chemical activity of the high pressure sodium arc, the arc tube is typically made of translucent aluminum oxide. High pressure sodium (HPS) lighting is vitally important to enhance the progress of flowering, budding, and fruiting. It emits a red/orange spectrum which sets off hormones in plants resulting in faster growth, bigger crops, and a larger harvest!
Initial lumen: 89,000
Color temperature: 2,100
Covers up to 4 to 5 square foot area,Places 12 to 24 inches above the plants
Socket: E39 base