315W Grow Light Kits

Free delivery on qualifying UK mainland orders over £50

315w bulbs are manufactured using ceramic metal halide (CMH) technology which has been specifically designed with plant growth in mind. The spectral output of CMH lamps is extremely balanced, producing light like that from the sun, while simultaneously rivalling the intensity of HID lighting. CMH bulbs are highly efficient, boosting yield and the varied spectrum increases quality. For more info on ceramic discharge metal-halide and how to implement them in your indoor garden, read our buyers guide below.

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Buyer's Guide

CMH/CDM 315W Grow Lights

Traditional HID lighting was originally developed as street lighting – professionals within the industry are migrating over to horticultural specific equipment due to the higher efficiencies that can increase yield in terms of both quality and quantity.


Ceramic lamps use a ceramic ignitor that can handle a higher operating temperature, allowing for a different mix of compounds within the bulb, allowing for a more balanced spectral output due to the inclusion of these different compounds.


Ceramic metal halide lights produce more light for the same electrical input compared with traditional HID, so you’ll recuperate the slightly higher costs of these fixtures in saved electrical costs over time.


Ceramic lighting can be used as a standalone option for your room, but the benefits of the balanced spectral output can also be seen when used a supplemental lighting alongside traditional HID. Great results have been seen when a single 942 blue bulb is used between 2 x 600w HPS fixtures.


We suggest you use each 315w to cover about a 1m2 area – The focus or sun system reflector is perfect for directing the photons on to the canopy in a square footprint while the horizon reflector works as a supplementary fixture, which throws light over a 1.2m x 2.4m footprint - Perfect for use in between 2 x 600w HID fixtures.


If you’ve got any questions about CMH lighting or how to use it in your garden, email us or call our specialist team on 0800 085 7995