There are a number of gimmicks offered with many LED grow lights which I believe can actually be harmful to your plants, your wallet, or both.
I personally feel that LED lights which let you adjust the spectrum is just a giant gimmick. In my experience, you're better off with the same spectrum for veg and flower, as long as it was the right spectrum to begin with. Having knobs, switches or buttons to change the color of the light is fun to play with, but any time you change the color of the light your plants are going to stress out while they get used to the new color.
You also aren't ever really getting a truly custom spectrum; all you can do is dim or brighten the specific colors of LEDs that the manufacturer put in to begin with, usually in batches of colors they already chose for you. If you want to add a different wavelength to your spectrum that wasn't already built-in to the light, the spectrum adjustment feature can't make it happen for you. You just can't get out something that wasn't put in in the first place.
I know many people will strongly disagree with me on all this, but I'd recommend trying out a full veg and flower run with the same, correctly-balanced spectrum yourself; you just might be surprised at the results. If you already have an adjustable-spectrum light, it could be as easy as turning all the knobs up or switches on and leaving them there for a whole run.
You may be surprised at the better yields and plant health you'll get by not adjusting the spectrum.
Dimming in the Morning or Evening
Kind LED's manufacturer also makes LED aquarium lights. Some have a built-in digital timer including a feature to automatically have the lights slowly increase in intensity when they come on, and decrease in intensity before they turn off. In aquarium lighting this is a neat feature because it replicates twilight and allows crepuscular (dawn- and dusk- active) animals to behave as they might in nature.
Kind LED incorporates this feature into their K5 LED grow lights. To their credit, Kind doesn't claim this feature helps plants grow better, but they do advertise it. From reading scientific research and my own experiences (I ran tests many years ago with low light in the morning and evening), it's clear that plants grown with less total light over the day give poorer yields than plants grown under full light. Several friends have tried this as well, and I haven't heard of anyone that did better with it. So, I consider this feature to be a gimmick. Plus, it requires you to use the integrated digital timer, which has serious issues as discussed below.
Herm-Inducing Integrated Timer
If you're growing plants indoors, you'll need a timer to turn your lights on and off, unless you're flawless in your ability to manually flip the switch at the right times each day. This is especially critical with daylength-sensitive plants such as Cannabis, and it is important to realize that it isn't the length of the day that these plants are sensitive to, but the length of the night. Without enough hours of un-interrupted darkness, these plants won't perform as they should.
Photoperiod-sensitive plants such as Cannabis use a pigment called phytochrome to determine night length, and phytochrome is sensitive to red light. This is why they sell all-green LED bulbs and flashlights for inspecting your garden at night; the green light won't activate the phytochrome and "wake up" your plants.
The Kind LED K5 series incorporates a built-in digital timer, which seems like a great feature to add to a grow light. However, the digital timer comes with a red LED display on the side of the light, which shines red light into your garden even when the timer has the light turned off. Had they chosen a green display, it wouldn't affect your plants, but the red LEDs shining all night could activate the phytochrome and "wake up" your plants, causing them to not flower properly, or possibly create hermaphroditic flowers in Cannabis.
Because it probably isn't that bright, it may only rarely cause problems, but why even gamble with that in the first place?
You really have to wonder what they were thinking when they offered a plant grow light with red LEDs that shine day and night. It certainly makes you wonder if they really are age old growers who spent years of research and development creating these lights, as they say on their "About" page. The research on phytochrome's preferential response to red light dates back to the 1960s, so apparently Kind's "research" wasn't terribly thorough.
Mixed 3W, 5W and 10W Chips that Just Don't Add Up
Kind LED offers 2 series of lights; the K3 series is all 3-watt LEDs, and the K5 is the perfect mix of 3W & 5W diodes. They don't specify the ratio of this perfect mix, but if we take the number of LEDs and divide by the total wattage to get the average watts they're running per LED, something very odd becomes apparent:
|Kind LED Light Models|
|Model||Watts||Number of LEDs||LED Type||Average Watts per LED|
|K3 – L300||220||90||3W||2.44|
|K3 – L450||270||120||3W||2.25|
|K3 – L600||320||150||3W||2.13|
|K5 – XL750||430||208||Mix 5W / 3W||2.07|
|K5 – XL1000||650||320||Mix 5W / 3W||2.03|
They are running the mix of 3W and 5W diodes in their K5 series at less average watts per chip than their all-3W K3 series!
No matter how they have the wattage divided between the 3W and 5W chips, this means that even the 3W chips in the K5 series aren't being driven as hard and generating as much light as the 3W chips in the K3 series, and the 5W chips might as well be 3W chips. Perhaps the "perfect ratio" is one 5W diode per light? I bet this is why they still need to add secondary lenses to all the LEDs for the K5 series of lights; whatever 5W chips are actually in there are just a gimmick.
Advanced LED offers the XTE series with a mixture of 3W and 5W diodes; the average watts per LED here is better than any of Kind's K5 lights and indicates that they are probably at least running the 5W diodes higher than the 3W diodes, but again something interesting appears with a second series of their lights:
|Selected Advanced LED Light Models|
|Model||Watts||Number of LEDs||LED Type||Average Watts per LED|
|XTE Series DS XTE 100 – 5W LEDs||91||36||Mix 5W / 3W||2.53|
|XTE Series DS XTE 200 – 5W LEDs||185||72||Mix 5W / 3W||2.57|
|XTE Series DS XTE 300 – 5W LEDs||274||108||Mix 5W / 3W||2.54|
|XTE Series DS XTE 400 – 5W LEDs||368||144||Mix 5W / 3W||2.56|
|Diamond Series XML DS XML 150||130||68||Mix 10W / 3W||1.91|
|Diamond Series XML DS XML 350||330||154||Mix 10W / 3W||2.14|
|Diamond Series XML DS XML 650||618||280||Mix 10W / 3W||2.21|
The XML series of lights with the mixture of 10W and 3W LEDs is pushing less watts through each LED on average than the XTE series' mix of 5W and 3W LEDs. What's the point of having these extra-powerful 10W LEDs if you're not going to drive them as hard as a mix of 3W and 5W LEDs? In my opinion, the 10W LEDs are just a gimmick.
Fluorescent UV Bulbs
California Light Works' Solar Storm series and Lighthouse Hydro's ION 8 lights both include UV in their spectrum, but they do this by including fluorescent UV bulbs in their fixtures instead of LEDs. UVA LEDs are expensive and UVB LEDs aren't really practical yet.
To me, one of the big advantages of LEDs is not having to change mercury-filled bulbs like you do with fluorescents and HIDs. I guess I'm willing to pay a little more to get UV LEDs to start with; they last longer and don't lose intensity like fluorescent bulbs — and lots of companies are starting to put UV LEDs in their lights or at least claiming to.
If you want to add UV to your garden and your LED grow light doesn't have it, or if your light has UVA and you want to experiment with UVB, you can go to a hardware or pet store and get a fluorescent UVA "black light" or a UVB "reptile bulb" to hang up. It will probably cost you a lot less than having the extra fluorescent fixture added to the LED light itself, will be exactly the same level of bulb-changing hassle and mercury contamination risk, and will allow you to put the UV light on a separate timer so you can get the right amount each day. If you're looking to experiment with UVB, you may want to check this out. And, don't forget to wear sunscreen and eye protection in your garden.