First 2x2 build question: DIY or QB?

[faust5]

Hey everyone,

I've learned a ton from reading this forum / blog, and I'm going to get a new light for a 2x2 setup! I used Mars Hydro my last grows and had serious stretching issues, so I'm really looking to have too much light rather than too little.

Here are my two options (feel free to suggest others):
1. The new QB 288 v2 RSpec LED kit.

• Pros
  • Uses Samsung LM301b and has supplemental deep red.
  • Everything included
  • Reputable manufacturer, etc.

• Cons
  • I think with that driver included, I'd have to run at full amperage to get ~120W (correct me if I'm wrong)
  • I'm worried about generating a hotspot, rather than having even coverage throughout the tent
  • I'm sure that's enough light for a 2x2, but I got burned by stretching on my last grow and I'd like the potential to go brighter.

2. DIY strip build with LM301b diodes. Specifically, I'd use the LT-Q562A 2' strips. On the DIY strip builds guide, LED Gardener recommends 7 strips for a total system power of 109.3W. Just to be overkill, I'd go with 10 strips for a maximum system power of 156W. This way, I could drive at 50% current for ~100 watts, and hopefully have everything be cool and efficient with the potential to crank it up.

• Pros
  • Uses Samsung LM301b
  • 22" LEDs in a 24" box for totally even canopy
  • Running at lower current could be cooler and more efficient
  • Building shit is fun!

• Cons
  • Cost, setup.

Questions:

1. Do you think the efficiency, canopy spread, and potentially brighter light makes the DIY route worth it? Keep in mind I think it would be pretty fun to build.

• What driver should I use to drive 10 LT-Q562A 2' strips? Should I wire it up in series or parallel? These strips aren't in the handy calculator, so I'm not sure what's the best option.

Thanks everyone!

[LEDG]

If it’s your first build, I’d go with the HLG to get your feet wet. Those things pack a lot of light into a 2x2. With this light, you’ll still get a taste for DIY and if you ever upsize your tent, you can then decide if you want to go full-on DIY or not.

If you need full power from this thing, you can run it wide open if you have enough height in your tent so it’s not making your canopy too hot. Otherwise, bring it closer and turn it down and enjoy higher efficiency.

[faust5]

If it’s your first build, I’d go with the HLG to get your feet wet. Those things pack a lot of light into a 2x2. With this light, you’ll still get a taste for DIY and if you ever upsize your tent, you can then decide if you want to go full-on DIY or not.

If you need full power from this thing, you can run it wide open if you have enough height in your tent so it’s not making your canopy too hot. Otherwise, bring it closer and turn it down and enjoy higher efficiency.

Thanks a lot for your reply! I'll almost certainly go with the QB288v2 Rspec.

Two quick questions:
1. Are the 660nm LEDs in the new QBs good / worthwhile?
2. If I did end up going with the DIY LT-Q562A strips, what driver / wiring strategy should I use?

Edit: Looks like I could potentially drop it back to 9 LT-Q562As, which at 22V in series gives 200V. @700ma, gives 141W output power at max. I think I could drive this setup with a HLG-185H-C700 CC driver (A or B?).

[unkle_psycho]

660nm should be a very efficient driver of photosynthesis, and adding it to 80cri leds makes the spectrum chart look much better, and increases cri without dropping efficacy. I have yet to see a single person say what exactly they expect this to do to the quality or quantity of their bud. Like we are starting to have real numbers on how uv is increasing THC, but on the red end of the spectrum most claims seem to be based on theory, rather then observation.

With everyone using the same diodes, theres really a lot of pressure for premium companies to differentiate. Its very hard to see where the line goes between the companies whos spectrum claims come from the research department, and those whos claims come from marketing.

I'm making a bunch of 2x2 lights right now, and while I think 120w is enough, I am making one to 150w, and plan to make one with the hlg185. Some versions of that driver put out 200w, which is definatly overkill, but I want to have one such light around to test light hungry plants etc.

[faust5]

I'm making a bunch of 2x2 lights right now, and while I think 120w is enough, I am making one to 150w, and plan to make one with the hlg185. Some versions of that driver put out 200w, which is definatly overkill, but I want to have one such light around to test light hungry plants etc.

Thanks for your reply! What strips are you using for your 2x2s? Have you posted the build / parts list anywhere?

[TEKNIK]

660nm causes stretch most of the time but also helps with photosynthesis, different strains will also act differently under heavy 660nm. My advice regarding spectrum is to fill in the gaps if anything is missing as the plants will adapt to the light but if something is missing it makes it harder for them to do it.

[unkle_psycho]

I'm making a bunch of 2x2 lights right now, and while I think 120w is enough, I am making one to 150w, and plan to make one with the hlg185. Some versions of that driver put out 200w, which is definatly overkill, but I want to have one such light around to test light hungry plants etc.

Thanks for your reply! What strips are you using for your 2x2s? Have you posted the build / parts list anywhere?

I've been doing quite a few builds lately, using the EB2 strips, but I've been lazy to post. Right now I paused my next order because the next gen is coming out.

I did a 2x4 build using an ELG-240 driver and 12 2 foot strips, then I did one to compare intense lighting, with 160w for a 2x2, using 4 40w TRP drivers, each driving 2 two foot EB strips.
One of my older builds is a set of kinda homemade QBs, that one I did a log on, I think it was 3ct vesta or something. Each light has 5 1 foot vesta strips driven by a 75w TRP driver. These guys have switches so you can choose between 2700k, 3800k and 5000k. I run 2 in a 2x2 space.
My next build I planned to make 2 fixtures, using the s6 and s7 spectrum strips from Koray on alibaba. The S6 has samsungs lm301b and epiled 660nm and violet (uv). The s7 spectrum has a large boost of 660, quite a lot of 730nm and what seems like too much UV. I wanted to make a fixture of each using hlg 185s, to compare high cri lighting. Now I'm putting that on pause and trying to get dedicated diodes for each possible boost freq, and a spectrometer, so I can test a bunch of side by sides.

[unkle_psycho]

660nm causes stretch most of the time but also helps with photosynthesis, different strains will also act differently under heavy 660nm. My advice regarding spectrum is to fill in the gaps if anything is missing as the plants will adapt to the light but if something is missing it makes it harder for them to do it.

I have quite a lot of bridgelux vesta, so I can already control the CT from 2700k, 3800k, and 5000k. Usually just run both channels on for efficiency, but it has been very useful at moments.

I think there needs to be a balance between the amount of red and blue, growmouse said studies at Fluence showed that to get the most out of the supplemental red, they had to increase blue a little too. Other frequencies also play in.

The plant adapts very well, but with time we will probably start finding spectrum related quality attributes. Already now studies are showing UV boosting THC, but instead of increasing UV, everyone is adding red.

There are quite a few lights coming out that allow playing around with frequencies. I'm quite interested to see what people come up with.

[TEKNIK]

660nm causes stretch most of the time but also helps with photosynthesis, different strains will also act differently under heavy 660nm. My advice regarding spectrum is to fill in the gaps if anything is missing as the plants will adapt to the light but if something is missing it makes it harder for them to do it.

I have quite a lot of bridgelux vesta, so I can already control the CT from 2700k, 3800k, and 5000k. Usually just run both channels on for efficiency, but it has been very useful at moments.

I think there needs to be a balance between the amount of red and blue, growmouse said studies at Fluence showed that to get the most out of the supplemental red, they had to increase blue a little too. Other frequencies also play in.

The plant adapts very well, but with time we will probably start finding spectrum related quality attributes. Already now studies are showing UV boosting THC, but instead of increasing UV, everyone is adding red.

There are quite a few lights coming out that allow playing around with frequencies. I'm quite interested to see what people come up with.

I am now using 4000K cri95 as a base, this covers pretty much all of the main spectrum. Mono colours and phosphor converted red will then be added to do spectrum control. The reason I am using such a high CRI 4000K is to get cyan as it's missing from most common colors. Cyan is also difficult to get in a mono. I am not concerned with efficiency now days and my focus is on spectrum. I have been playing around with this stuff for years to figure out what the ideal spectrum is for growth and my conclusion is that there isn't an ideal spectrum that suits everything all the time

[unkle_psycho]

I've been doing a lot of doubting the idea of a perfect spectrum here, I have actually been doing a pheno hunt and found 2 test subjects to really hammer the point through. I have found the slowest shortest node plant ever, an el chapo. Then I have the stretchiest green crack ever, it grows 15cm nodes under normal veg light. Want to see if I can find light recipes to get good growth out of them.

I think the entire market might start getting more interested in spectrum, and maybe a little less obsessed with efficiency. I just saw an article that one of EUs biggest players is going all in with Seoul's 100 lm/w 97cri tech.

Do you use cobs? In strips I wanted to try higher CRI and went for vestas, I see there are more options in COBs, but never built one. Right now I want to play around a little with discretes, and different rates of discretes supplementing white light. Supplimenting 80cri with discrete diodes seems the way to get the highest efficiency with a high CRI, but missing the cyan then. What do you expect the cyan to do?