The technology in grow lights is changing as even HID ballasts are even going digital and LED grow lights are gaining a lot more attention from the indoor grower. Why is this ? because of the recent advancements with LED lighting they are now brighter,longer lasting and a lot cheaper than they used to be.
LED lighting allows you to place the light much closer to your canopy as they do not produce any where near as much heat off the lamp as HID grow lighting.Now dont think you can get away with out using a fan and filter as heat is still produced and could affect your end results if sufficient extraction is not in place
As with hid lighting there are different colours in LED lighting that should be used at the right stages of your plants growth cycle. more blue should be used when your plants are in their growth cycle and red, orange in the flowering cycle.
Early LED grow lights used hundreds of fractional-watt LEDs and these were often not bright enough or efficient enough to even begin to be thought as effective replacements for HID lights. Now the newer LED grow lights on the market use high-brightness multiple-watt LEDs that are increasing the power consumption resulting in increased effectiveness of the technology leading to similar growing results to HID lights.
LED still cost more to buy than HID lighting but do cost that bit less when it comes to the running of the light. With that bit of money saving over the life time of the light makes them a sound choice that is why more and more people are giving LED lighting a chance to bring down running costs without losing quality or yields, using LED grow lights could be what we all end up using to grow indoors as the technology gets even better.
LEDs for me look pretty good when they are on because of all the nice brightly coloured lights but most of the people i have spoken to that have used them never said that they were getting the same quality or similar yields to that of HID grow lights. I think that LED grow still need to be improved on a bit before i would stop using my trusty HID lighting.