High Pressure Sodium Lighting

High Pressure Sodium (HPS) lighting has been a standard in indoor cannabis cultivation since the 1980s. These lamps emit a warm, yellow-orange spectrum centered around 600–610 nm wavelengths, commonly associated with flowering and fruiting stages in many horticultural applications. HPS fixtures operate at high temperatures and require ballast systems to regulate voltage, making them energy-intensive compared to modern LED alternatives. Breeders and cultivators working with HPS historically documented strain phenotypes, yield patterns, and light-response characteristics under this consistent spectrum. While newer lighting technologies have become available, HPS remains documented in many cannabis breeding records and cultivation protocols.

Lineage records and strain development documents from the 1990s–2010s frequently reference HPS-grown phenotypes, meaning certain strain traits and growth characteristics were selected and stabilized under this specific light spectrum. Breeders comparing old breeding stock to modern grows often account for HPS-era cultivation differences when evaluating genetic consistency.