Light is one of the most important components to any plant, so if you’re growing indoors, obviously lighting is one of the biggest decisions you have to make for your plants. The two most common types and also most popular in the green world of growing are HID and LED. Just like with everything else, every person has his or her own opinion on what’s better and the stuff to prove it. BCNL wanted to get to the bottom of this and try to figure it out as definitively as possible, so we asked a professional to put LED against HID lights. To do this, BCNL’s grow tester Eldon Perdue used two BC Northern Lights grow boxes to measure efficacy of HID vs. LED lights for vegetation and bloom phases. HID lights in one box, and LED lights were placed in the other. To make sure the experiment was legitimate, we had to make sure that both boxes had the exact same variables so that the results were as close to being accurate as possible. So, both boxes drew the same amount of power (two light fixtures at 400W, each, with a 800W total), their plants were fed the same amount of nutrients, the boxes stayed at 70°C, and they were treated exactly the same. If HID Box got a bit of water, so did the LED box. Eldon’s experiment ran for seven weeks. These weeks do not include planting and harvesting. Each box started with 12 plants each, with clones from a mixed quality of plants (Sensi’s Hindu Kush, 90% Indica dominant), but all the clones were split up evenly between the HID and LED boxes. Some had one or two ones, and others had four or five. In the six available columns in each box, the two centre columns were left empty. The clones, which were originally in one-inch rockwool cubes, were planted in coco coir, then left under the 125W CFL bulb for a full 24-hour cycle for two weeks. This was done so that the clones could acclimate to their new environment. Both were given the same advanced nutrients (pH Perfect Grow Part A&B, pH Perfect Bloom Part A&B, Tarantula, Piranha) and vitamin institutes (superthrive). The BCNL boxes used featured a 10 ft. x 10 ft. space, ductless air conditioning, watered through reverse osmosis and CalMag Plus to 200-250 ppm as the base, and the same external light-box exhaust. By the third week, both sets of plants were healthy and ready for full vegetation. In the HID box, MH bulbs were added. LEDs were powered on in the (obviously) LED box. Both were started on 18/6 light cycles. Though Eldon witnessed differences in the first week of the plants’ bloom phase, these differences were fairly minimal. The HID lit box grew healthy foliage, while that of the LED box just burnt. But despite this damage, the nodes of the LED-illuminated plants the nodes grew close together, and their root systems looked pure white and growth was consistently good throughout the box. In the HID box, the health varied across the plants. The stronger plants had healthier roots and the smaller plants and insufficient roots. It was during the second week of the bloom phase when Eldon came across significant differences between the HID-lit and LED-lit boxes. The HID box plants were in the vegetative state for too long, but grew very fast. Eldon had to tie the taller plants down to prevent them from reaching the top of the box. Ultimately, Eldon couldn’t keep the two boxes on the same cycle because of this growth. The foliage eventually looked to be heartier, but the health was still inconsistent all across the plants. LED box plants, though, didn’t grow as tall as the HID box plants. In fact, they grew to be short and stocky, but were consistent in terms of height and quality. By the fourth week, the plants were completely different. HID-lit plants flowered denser and fatter than those of the LED-lit plants. The entire grow box was filled with plants. The LED box plants remained short and stocky, and gained little to no height during the plants’ flower phase, though they were nonetheless healthy. Regardless, these bud clusters were less dense than HID-lit plants. By the fifth week, it was obvious that the LED box won’t be making any gains. Still short and stocky, they did manage to gain a little bit of density. In comparison to he HID-lit boxes, though, the growth of the LED-lit plants was essentially negligible. Because the LED-lit plants were vertically challenged, they weren’t able to take full advantage of the light intensity in the upper ranges of the grow space, growing only to half the height of the BCNL grow box. At the end of the experiment, Eldon harvested 14 ounces of LED plants, and 21 ounces of HID plants, out of a total of 35 ounces between the two boxes. The HID plants produced larger, denser buds from fewer plants. Numbers don’t lie. The HID lights yielded more growth. So, do you guys have any personal experiences with LED vs. HID? Conducted your experiments? What did you find?