I have never researched DIY LED lighting but the most impressive grow thread I ever followed was a totally LED grow. Several years back, on a similar board that is now defunct, a member came into a tidy sum of money and decided to dump his HID lighting and switch to LED lighting. He researched to find the very best LED lights and he purchased a good number of different styles.
Above his plants he had two large LED panels. He built what I call portable posts for the lack of a better term, 4 X 4 posts cut in sections that would stack on top of each other, with a flat piece of plywood attached to the bottom of each portable post set for balance.
Each section of stackable post was long enough to hold an LED light bar. On some portable posts he attached LED light bars to one side and on others he attached LED light bars to all four sides. He ringed his plants with portable posts with an LED on one side and once the top LED light panels were raised high enough he added more portable posts with LED light bars on all four sides between his plants. Each time the top LED lighting was raised enough for another section of portable post with more LED light bars on them he would add another section.
His plants were the thickest most lush plants I have ever seen grown indoors. The colas were massive and the buds on the lowest portions of plants were as large or larger than most I see people get just under the bottom of their colas, meaning larger than most people’s very biggest buds other than colas are.
The key to LED lighting is to purchase the highest grade LED lights available and to purchase them in sufficient numbers AND then use them in a way that they will be able to do the very most they can for the plants growing from their light.
If people did that they would throw rocks at CFLs and HID lighting and never use either ever again. In most cases people purchase low quality LEDs because of price, and purchase too few of them, again because of price, and then they tend to expect too much from them and use them incorrectly. The result is a bad rap against LED lighting when it should instead be on those who should never have spent their money on LED lighting in the first place considering how they did it.