Page 1 of 1
COB advice for a beginner
Posted: Sat Sep 14, 2019 6:20 am
by grumps
Hello everyone!
I'm growing carnivorous plants indoors on a 1.5x4ft
wire rack . So far, I've been using a mars hydro 300w, but it's now time to get LEDs for the next shelf of the wire rack and I'm interested in LEDs with more efficiency that hopefully give me more control on how the light is distributed. This is why I want to learn more about COBs (and LED strips, but that's for another topic).
I'm aiming to put the lights somewhere between 12 and 24 inches above the plants and I'm hoping to achieve a PPFD between 200 and 400 umol/s/m^2 (higher would be fine but not necessary) throughout the growing surface. Some of my plants prefer 200 while some prefer 400 so some variation is OK.. I don't have experience with DIY LEDs but am comfortable with electronics.
I would really appreciate advice while designing this COB set up and I come with many questions:
- Any advice on choosing COBs? I imagine I'd end up needing 4 or 5 but may only get a few at the beginning and then get more lights as my plants grow in number. Could a Luminus CXM22 be a good starting point or would I need a CXM32 (or do you recommend other brands/models)?
- What CRI is best for plants (does it even matter)?
- What color temperature is best for plant growth? I'm interested in optimizing efficiency and usable photons.
- How can I tell if a heatsink is large enough for a COB?
- Any advice on where to purchase parts from?
I'm not sure if these are good questions but I'm hoping to open a discussion with more experienced people. Thank you!!
Re: COB advice for a beginner
Posted: Sat Sep 14, 2019 2:13 pm
by The_Mouse_Police
Have you considered strips and panels?
Plants don't care about CRI itself, but higher is better, all else being equal. If you check out the spectrums, higher CRI tend to have more deep red, and depending on CCT, more cyan and green. But, some emitters do things a little differently, so you want to get at the graphs.
The best CCT, all else being equal, is much debated. But, 3500-4000k is a pretty safe bet.
Re: COB advice for a beginner
Posted: Sat Sep 14, 2019 11:18 pm
by grumps
The_Mouse_Police wrote: ↑Sat Sep 14, 2019 2:13 pm
Have you considered strips and panels?
Plants don't care about CRI itself, but higher is better, all else being equal. If you check out the spectrums, higher CRI tend to have more deep red, and depending on CCT, more cyan and green. But, some emitters do things a little differently, so you want to get at the graphs.
The best CCT, all else being equal, is much debated. But, 3500-4000k is a pretty safe bet.
Thanks!
Yes, I've also been considering strips and panels. The QB120 quantum board seems like a potentially good solution, but perhaps the extra flexibility/cost savings of a DIY setup is worth it. I posted a
separate thread to ask the experts here about LED strips.
It sounds like COBs may have been more efficient a few years ago but LED strips are taking the lead in 2019? Would there be any reason to continue to consider COBs or are LED strips clearly the way to go?
Re: COB advice for a beginner
Posted: Sat Sep 14, 2019 11:28 pm
by TEKNIK
I gave up on cobs a few years ago, they were good bang for buck but so many strip options now and they give a much better spread. A cob can not compete with efficiency or spread of good LED's. I was looking at some LOBs this morning and they say they are getting really high efficiency but I think that's bullshit. Alot of bullshit in this industry and the only way to check things properly is to put it on a proper test machine.
Re: COB advice for a beginner
Posted: Wed Sep 18, 2019 3:15 am
by slayking0113
Yeah, I don't know much about COB, I only use the LED light now, high efficiency, also mars hydro, their new light. If your first time, why not buy it directly? there are also some great cobs in the market now. I love mars, their sales send me the email just now, that they have a special offer to
cob, order one and send free one. Good luck, get your best light
Re: COB advice for a beginner
Posted: Wed Sep 18, 2019 6:15 am
by TEKNIK
Mars does not have good enough technology, stick to the major brands for COBs, don't risk a fire hazard
Re: COB advice for a beginner
Posted: Sat Sep 21, 2019 3:53 am
by slayking0113
TEKNIK wrote: ↑Wed Sep 18, 2019 6:15 am
Mars does not have good enough technology, stick to the major brands for COBs, don't risk a fire hazard
Have you used it before? So their technology is not mature now? They have the buy one and send one free light, only 240usd,it attracts me so much, I want to build a new room, use the COB, hesitate, so hard for me to choose the light
. Do you have any other recommendations? Thank you so much, dude
Re: COB advice for a beginner
Posted: Sat Sep 21, 2019 3:55 am
by TEKNIK
You can buy COBs for $10 each that will be higher efficacy than what they are doing to that COB. Read through this section properly
Re: COB advice for a beginner
Posted: Sat Sep 21, 2019 4:22 am
by slayking0113
TEKNIK wrote: ↑Sat Sep 21, 2019 3:55 am
You can buy COBs for $10 each that will be higher efficacy than what they are doing to that COB. Read through this section properly
Thank you, TEKNIK, a great help to me.
Love peace and hemb
Re: COB advice for a beginner
Posted: Mon Mar 30, 2020 7:10 am
by randorson
grumps wrote: ↑Sat Sep 14, 2019 6:20 am
Hello everyone!
I'm growing carnivorous plants indoors on a 1.5x4ft
wire rack . So far, I've been using a mars hydro 300w, but it's now time to get LEDs for the next shelf of the wire rack and I'm interested in LEDs with more efficiency that hopefully give me more control on how the light is distributed. This is why I want to learn more about COBs (and LED strips, but that's for another topic).
I'm aiming to put the lights somewhere between 12 and 24 inches above the plants and I'm hoping to achieve a PPFD between 200 and 400 umol/s/m^2 (higher would be fine but not necessary) throughout the growing surface. Some of my plants prefer 200 while some prefer 400 so some variation is OK.. I don't have experience with DIY LEDs but am comfortable with electronics.
I would really appreciate advice while designing this COB set up and I come with many questions:
- Any advice on choosing COBs? I imagine I'd end up needing 4 or 5 but may only get a few at the beginning and then get more lights as my plants grow in number. Could a Luminus CXM22 be a good starting point or would I need a CXM32 (or do you recommend other brands/models)?
- What CRI is best for plants (does it even matter)?
- What color temperature is best for plant growth? I'm interested in optimizing efficiency and usable photons.
- How can I tell if a heatsink is large enough for a COB?
- Any advice on where to purchase parts from?
I'm not sure if these are good questions but I'm hoping to open a discussion with more experienced people. Thank you!!
*Are you flowering plants on the rack? How many shelves per rack?
*Seems like linear strips would be a better choice.
*I think we probably all agree that theoretically, all other things being equal, higher CRI is better.
*Color temperature can affect plant growth pattern and morphology. Typically for plants that flower in the fall, people consider using bluer temps during the vegetative growth portion of the plants life, and warmer/red temps during flowering. 3000k or 35000k are common color temps for lights used to flower cannabis, although warmer temps are not all that uncommon.
* You probably aren't aware that you are asking a question that is difficult to answer concisely.
https://ledgardener.com/find-heat-sink-cob/