The bulb you buy must match the wattage of your ballast. Bulbs are available in
Metal Halide (Blue spectrum for vegetative Growth) and
High Pressure Sodium (Red Spectrum for the flowering stage).
Conversion Bulbs are also available, so you can get Metal Halide light from a High Pressure Sodium Ballast or vice versa.
We carry:
Sodium bulbs: Hortilux • Digilux • Agrosun
Metal Halide bulbs: Hortilux • Digilux • Agrosun