Metal halide for flowering?
By Ed Rosenthal - Thursday, February 13 2003
I know your advice is to use high-pressure sodium lamps for both vegetative and flowering cycles.I have two 250-watt metal halide industrial lamps. I can't afford to buy HPS units because in Britain they cost $150 a piece without lamps.
Can I use my MH lamps successfully from start to finish? Will the crop be worth the smoke? Why is the HPS lamp better?
Shpinkter,
Great Britain
Metal halide (MH) lamps can be used for flowering, but there are two problems that they have when compared with high-pressure sodium (HPS) lamps. The first is that they don't emit as much total light. HPS lamps emit more than 20% more light, so MH lamps are not as intense when covering the same area. Second, they do not emit as much orange and red light as HPS lamps. These spectrums seem to promote flowering.
However, MH lamps do have several advantages over HPS. First, they are less expensive to purchase. Second, the light does not have a really weird telltale
spectrum. It looks white, not pink or amber.
Third, the lamps emit more UVB light than HPS lamps, although still in very small amounts. The amount of UVB light plants receive is directly related to the quality of the buds. The more UVB, the higher the quality.
Buds grown under MH light will not be as big as buds grown using HPS lighting. However their quality will be as good or better.
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