I’ve been growing marijuana for a long time now, well just over a couple of years, and because I am considered one of the more experienced growers I often get asked questions by new growers, and one of the most common questions I get asked is; “What type of LED grow light should I look for?”
Well, first things first: take a look at our front page for the list of Top Ten Grow Lights for this year.
I constantly try out new LED lamps just so I get a real feel for what’s out there on the market. But hey I’m not here to sell you on any single brand, right now what I want to talk about is what you should look for before you put in any $$.
The LED Chip
You always want to look for chips that are at least 3W, any less than that won’t give your plants enough consistent light coverage. This means each chip needs to be 3W, not 3 lights of 1W LEDs, so look out for that when reading the description. The 3W chip offers the best quality in whites, blues, and reds.
This is also important; you want to read product descriptions for total output. How many units does the lamp claim to have? This can be 300W, 400, 600, or even 1000. Always check for the output and look for at least 300W.
Understand that when it comes to LEDs you can’t always get 100% power so you usually end up with slightly less wattage than what the recommended is, and chips will always burn out, no matter what the quality, so the higher the wattage the more you can compensate for wattage loss.
Remember that it is the red blues, IR, and UV that also counts when growing your marijuana crop, so you want to stick to the ideal PAR values. Look for blues that have a range from 440-470nm, with reds in the 640 to 660nm.
These lamps stay on for the better part of the day, often 18 hours at a time, so you want to make sure they have internal fans that protect the lamp but also those that protect the plants. If it gets too hot in there you could damage your plants.
LED lights run cooler than HPS bulbs as they only let off about 15 to 25 % of the energy as heat, but the heat occurs behind the bulb in LEDs, and that area needs to be protected. A good quality lamp will have a thick aluminum heat sink attached to the back exterior or interior area which forces the heat away from the chips. This is now common in quality lamps that no longer need fans. Not only does this reduce running costs but also the noise that was common with lights with fans.
Good quality lamps will have an optical lens that magnifies the light-giving about 25% more penetration of nutrients for the plants. This makes for a more expensive lamp but is certainly worth the price.
The LEDs should have a warranty, preferably one of 3 to 5 years. In fact, LEDs of this nature are supposed to have a life span of about 10 years, especially in some of the more expensive panels. Look for panels that are sturdily built with aluminum, steel, or materials that won’t easily break.
Look for lamps with more than a one-year guarantee, as I mentioned before, LEDs are made to last up to 10 years, so I am somewhat suspicious of manufacturers who only offer a one-year guarantee, as this is an indication of a cheaply made housing or cabling system. I usually look for a 3-year guarantee on parts.
The parts guarantee is better anyway because the lamp will continue to work regardless of the part that needs replacing. You can easily replace the missing part yourself when it arrives, and in the meantime, your plants still get the nutrients they need.
Hopefully, this gives you some insight as to what to look for when considering the different LED grow lights for your new marijuana crop.