right i have had a look through a good few forums and i have a few questions as i cannot find them in the faq's. apologies if they are already there. Im one of these people who needs to know why he is doing what he is doing so i can try to improve. The plants need light, however is this light of any kind or do specific bulbs need to be used such as the ones mentioned in faq's CFL's etc.? In a hypothetical situation would household light bulbs work if there were enough of them? i read that 100w's is needed per plant, is this a hundred watts of any kind? This probably didnt need a new thread apologies for cluttering the forum!
not really. It needs to be the right wavelength, and thus, the right color spectrum. The problem with incandescent lightbulb is it puts out way too much heat to be use closely to the plants. CFL's can work, and even normal floro tubes have been used successfully. Unfortunately my brain seems to be lacking as i cannot remember the peak wavelengths that photosynthesis uses, but 6800 k is about the right color temp i believe.
There is absolutely no way you have done due diligence and did not find information about the kind of light needed for growing. <sigh> Household bulbs won't work -- wrong spectrum and too much heat. For vegging you need light around 6500k color temp, which is very blue-spectrum light and simulates the sun's frequencies in mid-summer when it is high overhead. For flowering you need color temp around 2700k, which is very red-spectrum light and simulates the sun's frequenices in autumn when it is lower on the horizon. Fluoros (including CFLs), metal halide, and high-pressure sodium are very efficient at delivering certain of these spectra with relatively low heat per light output ratio. Rules of thumb about watts per plant assume you are using these kinds of lights. And in the case of CFLs, which often are marketed with the "equivalent" watts meaning equivalent light output, go by the actual watts not the equivalent watts. You may want to try reading through the grow guides one more time.
i wasmerely nterested why, thank you for aswering my questions. where can i purchase CFL's at the correct colour temp in the uk for cheap?