Best light for a 3x3x6
- Thread starter Frank Nitty
- Start date
LEDTonic - Daniel
Active Member
Red boost primarily helps when light intensity levels aren't adequately high. Above 500 PPFD, red boost is only marginally helpful, if that. It seems to be a fad that lamps "need" to have red boost but science says otherwise.
UV should not be used from seed to harvest. It's also important to differentiate between UV-A and UV-B. These wavelengths do different things to the plant and should only be applied when appropriate. Therefore a standalone UV-A/B lamp with its own light schedule is far better than integrated UV diodes that are on the same hours the main lamp is on.
I don't have a source but some say that UV diodes also have a significantly shorter lifespan than other diodes, eg white. White Samsung diodes will last 50.000+ hours assuming that they are running relatively cool. I've heard UV diodes (brand dependant, of course) last 1/5th of that time. Again, I don't have a reliable source for this so take this with a pinch of salt.
Hope this helps.
V256.420
Well-Known Member
So essentially, no matter where you get your UV/A or B from, either LED or a T5, you need to have them on their own timer. Better to NOT have them incorporated into the fixture? Am I getting this right?
LEDTonic - Daniel
Active Member
Correct.
I'll add a caveat. If you buy a lamp with integrated UV diodes, regardless of brand, I'd ask for a written (email) confirmation from said brand that the UV diodes will last equally long as the other diodes on the lamp. I don't want to generalize and say all brands of UV diodes only have a short life span but from what I gather, some/most of the UV diodes used in today's grow lights won't work as long as white diodes.
I'd also only buy a lamp with UV diodes IF these have their own timer and can be switched on/off independently from the other (white) diodes.
But again, if one is to experiment with UV-A and UV-B, I'd recommend doing so with a standalone UV lamp. Also keep in mind that UV is more harmful to human eyes than blue (and white) light so turn off the UV when working near your plants.
V256.420
Well-Known Member
Very nice to know. Thank you very much for this. This is not the first time I'm hearing about the timing situation with UV and your regular flower fixtures. I was told by someone else using the Agromax T5 fixture that you should only use UV sparingly and be very careful with it. I assume it would be the same for a UV LED.
What kind of timing would you recommend for the HLG 30 watt UV bar as an example? It has it's own power cord so you can hook it up to it's own timer.
LEDTonic - Daniel
Active Member
You're welcome. Information should be shared so we call grow as... growers.
Right. As long as the emitted spectrum and intensity is identical or similar, it doesn't matter if you're using a T5, LED, or whatever else you fancy.
I'm not knowledgeable enough about UV to give definitive advice. I always recommend growers to contact the brand they bought their lamp from. If a brand sells a certain product, they should also be able to offer support and advice, and know the facts.
The growers I've talked to about UV usually only use the UV for 30-60 minutes a day. I don't dare to say if this is best practice but that should give you an idea at least. I'm sure there are growers on this forum who are more knowledgeable about UV than I am.
Frank Nitty
Well-Known Member
That light is going to cost a fortune
Rocket Soul
Well-Known Member
This is quite interesting re spectrum, can you maybe quote the source with links?
end_of_the_tunnel
Well-Known Member
I would be interested in sources too. Added red has me fascinated. I am always searching for info, be it anecdotal or research based.
Always understood the selling point for added red was to boost plant processes, besides boosting efficacy/efficiency numbers.
LEDTonic - Daniel
Active Member
Sorry for the late reply. Time doesn't permit me to visit ROI as often as I'd like.
This article is circulated in the indoor growing community:
(PDF) Green Light Drives Leaf Photosynthesis More Efficiently than Red Light in Strong White Light: Revisiting the Enigmatic Question of Why Leaves are Green
PDF | The literature and our present examinations indicate that the intra-leaf light absorption profile is in most cases steeper than the photosynthetic... | Find, read and cite all the research you need on ResearchGate
www.researchgate.net
While I recognize that a single article is not definitive proof that a theory is a fact, and other grow conditions certainly also impact final yield, the thoroughness of this study still impresses me. Enjoy.
AussieLEDs
Member
Here is a 3 x 3 LED I built using Bridgelux Vero19 1750k COBS and Bridgelux EBGen2 3500k / 4000k Boards (8 x 1' Strips)
Awesome looking rig man.
Your pic has potentially inspired me to DIY myself if I ever go through a redesign of my current setup.
Sqwee
Well-Known Member
Are you running them full out? I have one in a 3x3 and have some heat issues with it and have to keep it dimmed around 60%