A 250 Watt High Pressure Sodium [HPS] "Son-T" lamp shown bare and in protective packaging. Also shown is a 250 Watt Metal Halide [MH] lamp.

Please note that 250 Watt lighting is considered extremely low powered for hydroponic applications and should only be used for a small area (and correspondingly small number of plants). For general hydroponic use, we strongly recommend the use of 1000 Watt lamps in lighting systems. Should you wish to use 250 Watt lighting due to having an extremely limited budget, please be aware that plant yield will suffer. Plants can only grow using the energy received from lightsources. Typically, for all plants except shade loving plants, this can be as high as 1000 Watts per square metre, although 600 Watts per square metre is considered acceptable. Therefore, a 250 Watt lamp should illuminate an area no larger than 5/12 of a square metre. Illuminating a larger area will not increase plant yields, but will slow plant growth and therefore increase risk of disease. Likewise, packing more plants into an area does not increase the yield. Less energy is wasted when the plants are very small, but the plants compete for the same energy once they become larger. This can create a very inconsistant crop if some plants are allowed to outgrow surrounding plants.