Red LED grow lights


I purchased a grow tent kit and it came with red led lights
Is it better to use this light at all times or only when blooming starts
I have been told that later is better ???

Two 250 watt cfl one at 6400lum one at 2700 lum

Does it truly only have red lights only? Or does the over all light look red-ish but it might have some blue diodes and maybe even orange or white diodes as well?


What type of LED lights? This could be important and a picture could help.

If you are talking about the cheapo all red LED light panel, that is about a square foot and that has lights in it that look similar to LEDs used in regular flashlights, toys and the new Christmas tree strings, then that is not a good light for almost any tent bigger than about a square foot, or a cubed foot as the case might be. And it would not be good at any time completely on its own. A plant does need some blue light, about a minimum of 30-35% blue to red, at all times to stay healthy. In general, more light is needed during flower than in veg, and blue light is a little less important during flower, this is the only reason you see flowering lights that maybe seem more red than veg lights.


this is the description of the light is
CG40x5 grow light , Powerful 6 band , with IR, light spectrum , 5w led diodes


It sounds like it very likely has 2 spectrum of red, 2 of blue and 2 of white. Loosely and in layman’s terms a deep red, lighter red, a deep indigo blue and a lighter blue, and a redder white and a blue-er white. This would make the most sense as a guess, without you listing the actual nanometer specs of the red and blue diodes and or Kelvin ratings of the white diodes, if it has them. It likely has 40 of the 5 watt diodes.


This also means it might be labeled as a “200 watt” light – as 40 multiplied by 5 watts is 200, but it may very well only use about 100 actual watts.

With a good balanced LED system, like this one might be (assuming it does have all the previously mentioned spectra and in the correct proportions), you want about 35 actual watts per square foot of your plant’s canopy. It may very well be full spectrum and therefore good for veg and flower, equally, and maybe good for about 3 square feet.

Hope this helps,



I bought a couple of these off ebay, 300watt equivalents(280 watts useage), and have used them for about a month, everything seems okay with them,

I use them on each side of a 600 watt equivalent IPower led light that seems more white than reddish, in a 4x8 foot grow tent, meaning each 300 watt lamp hangs over the ends of the tents, the other brand 600 watt in the middle, and I have no idea this is good, plants seem to be recovering from previous cramped space though. Mine use 3v leds, and were shipped from California, not directly from China.

I mean, the auction page, they talk all about full spectrum, hopefully they aren’t a bunch of lying cheating pieces of human garbage, but eh, one can only hope to get something that is purported to work good for sure in the long run(fingers crossed).

Here is the dimmable version of the 300 watt lights, very interesting, I am inexperienced to know if these are better to have due to dimmable function, I suppose it would be good all around for young clones and such, or dimming a few of these for vegging then brighten for flowering, unsure if that is what is compatible for flowering of marijuana, I have loads of books and have been too ill a lot of times to read them, or I spend too much time when I am feeling good doing other things.



OK, if you have been paying attention, the label watts isn’t even “equivalent” watts in these types of LED systems. It is labeled 300 watts because it has 100 individual 3 watt diodes. These diodes are rated up to 3 watts before they will burn out, but they usually only are run at maybe just barely above 50% capacity, so your light will not be using 280 watts each, more like around 150 watts. If you look in the details of the description, it actually only uses approximately 165 watts each. This is probably true of the dim-able version, only 165 watts at full brightness.

The i-power 600 watt unit is also probably only using around 300 watts.

They are probably decent lights, just keep in mind the watts is not anywhere close to what you had previously stated and keep in mind, you need about 35 actual watts, maybe you can get away with 30, with LEDs per square foot.


Yeah, thanks mac, for the math, I have read here the “per square foot” thing before and have a hoard of books, but I have had a run of poor heatlh again lately, including the chronic migraines, reading/internet sets my problems off more. I was almost thinking they aren’t enough, I am still on the fence whether or not I will remove the led lights and install my hps lights for flowering, I debate it in my mind a lot. I had to blow almost a hundred dollars the other day on soil on sale and five gallon pots, and some other gardening gear, I mean, that money could have been better spent on at least one more 300 watt led light.
I have an hps ducted assembly at 600 watts, claimed at 5x5 foot coverage, and a winged ducted 600 watt assembly rated at 4x4 foot coverage, so at 1200 watts, I suppose I would be “safe”.


@budbd, I’m a big fan of well built LEDs. And with some hard research, I don’t think it is difficult to find a good light at a good price, even at dealzer:

and there is something to be said about the top of the line systems that have the LED diodes combined with lenses for better focus and canopy penetration, and for many, the extra expense is well worth the added efficiency and effectiveness.

Personally, I would just get another one or two of those 300 watt LEDs, I have seen other “300 watt” LEDs like that one for around that price, or just under the $65 USD price range even, and they seem like good lights, even with some of the better known names that sell twice the price elsewhere, like “mars hydro”.

I’m thinking the price has finally come down on some of these to make the savings on dealing with heat and extraction fans and overall electricity usage, that I’d not even recommend HID lights to smaller personal growers at all anymore.


Ah, I think I must have been off my rocker on the “wattage outpuit” for led lights, meaning I thought that when they said they were a 600 watt light that they put out the equivalent light/lumens as a standard hps or mh light, but they never mention those. So really, in the tent with leds, I have two 300 watt lights really at bout 150 each watts, and one 600 watt consuming 300 watts, meaning I got about 600 watts “lights” worth, same as if I had a single hps light hooked up!. If I am correct on that, I mean, darned, I can refer to my books, I can’t believe how screwed up my thinking is lately, I mean, probably the pain med pills screwing up my thought processes. So, knowing I am doing a real 600 watts I could do with two more led lights, at bout 150 watts light output each to make about 900 watts light output from 1800 watts worth of led purported advertised max wattage, AND I don’t think I can afford it right now, …blew lots of money recently on other hobby goods I bought on once in a lifetime prices, all in one month. I should have two more cheap led lights, 2x300 watt style, and won’t spend the extra money for dimmable style, cause I just don’t understand why I would need dimmable led lights I am pretty sure I will flower with leds now.



@budbd, I’ll leave it here for now, it seems appropriate, as even @Hawkins original post turned out to not be just about Red LEDs. And yes, this thread has some good info about LEDs in general.

LEDs can be more efficient than HID lights, when comparing watt to watt.

HID, that includes High Pressure Sodium and Metal Halide, the standard is to shoot for 50 watts per square foot.

With high output florescent lights, like T5s and CFLs, you can get away with using as little as 40-45 watts per square foot. This is partially because they do not get as hot as HID and can be moved closer to the plants increasing the intensity, not so much that they are more intense per watt.

With a good LED, you can get away with as little as about 30-35 watts per square foot. This is also because you can get them closer. And LED and HPS are about the same as efficient if looking at the exact electricity to light conversion efficiency, but LED can be tailored to a more effective light spectra and all of said electricity can be made in PAR, or “photosynthetic active radiation”. As I’ve said before, roughly light can be described as being made from blue, red, and green light, and so a lot of energy is being saved by not turning some of that electricity into wasted green light. A HPS may look yellow, orange-ish or red-ish, but a lot of that is from unwanted green light, yellow is getting closer to, and from the green part of the spectrum. And so the 15-20 watts savings in 30-35 watts for LED as opposed to 50 watts HID is because you are not having to spend it on the nearly 1/3rd or 33% that would be wasted in more white light, from the green part of the spectra.

But, yes, you won’t go wrong necessarily, with trying to get the same actual LED watts in your room, as you would have with your HID watts. And btw, a HID 600 watt would probably be using actually more than 600 watts because of the ballast, it uses a lot of watts itself.


Wow, thank Mac, man that is indepth information, and it is sticking, I mean, I feel like I am going to marijuana university when I visit here. I am gonna print this out so I can refer to it, along with the need for more study of some of them books I collected that are instead collecting dust.