These bulbs require a suitable 400w HPS ballast or they will not light. These bulbs are probably the finest value grow bulbs on the market and can be used throughout the whole growing cycle. Please keep in mind that all HPS and MH bulbs require a suitable ballast and can not run direct from the mains without one.
Long life 400w HPS (High pressure sodium) replacement grow light bulb
These bulbs need a suitable 400w HPS ballast or they will not light.. Ideal for growing all kinds of plants and ideal for flowering and budding stages of growth for maximum crop yeild
240 volts 400 watts. E40 bulb fitting. (The screw is one and a half inch wide). If your fitting looks like this then you have the correct one
As with all bulbs of this type you must not touch the bulb glass with bare hands as it will leave fingerprints which will cause hot spots and shorten bulb life. Not to be used without a suitable 400w HPS compatible ballast. If you are not sure what this means please read up before buying this bulb as it will not work otherwise.
Bulb must be used with a ballast unit suitable for HPS bulbs and cannot be used direct from 240 volt mains