Before I drop a grand on a DIY setup some advice would be helpful.

Porky101 said:

I agree with what is said above, from experiance, above 1,000 umols you get spots that look like CA def. Also seems to slow flowering time and reduces yield.

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I cut my coco with 15% compost (and 15% perlite) that is extremely high in calcium, also my water source is usually tap that has been allowed to dechlorinate by sitting for over 24 hours, and my base compost for my nutrient teas is Lobster compost, which is obviously rich in calcium, so tend to avoid having such issues when running similar intensities with HPS and CO2 back in the day.

Randomblame said:

I would prefer 3500 or 4000°k/CRI80 to keep the plants short, strong an bushy and to fill both trays completely.

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I really appreciate this insight. I’m probably going to either prove you correct and learn the hard way about applying an enhanced spectrum during the second half of flowering, or my hypothesis that it improves flavors, potency, and yields will be confirmed. I noticed that the median point between 2000k and 5000K is 3500K I’ve attached the SPD’s of the two boards and you’ll see how when matched together it’s practically the perfect SPD for flowering cannabis. I think though that the method I am going to use to arrive at 3500k by a fuller and wider spectrum at pretty good lm/w etc. will benefit them. Because of this thread I’m probably going to use 3500K Samsung Q strips for the first half of flower, because stretch control is important and they’re super good at turning electricity into photons.

Are there any specific potentiometers that you recommend for dimming?

TaxesR4Loserz said:

I really appreciate this insight. I’m probably going to either prove you correct and learn the hard way about applying an enhanced spectrum during the second half of flowering, or my hypothesis that it improves flavors, potency, and yields will be confirmed. I noticed that the median point between 2000k and 5000K is 3500K I’ve attached the SPD’s of the two boards and you’ll see how when matched together it’s practically the perfect SPD for flowering cannabis. I think though that the method I am going to use to arrive at 3500k by a fuller and wider spectrum at pretty good lm/w etc. will benefit them. Because of this thread I’m probably going to use 3500K Samsung Q strips for the first half of flower, because stretch control is important and they’re super good at turning electricity into photons.

Are there any specific potentiometers that you recommend for dimming?

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Are you trying to have seperate dimming or link them all? I would imagine seperate. Rapidled has a nice 100k pot in a plastic case for like 6$. If dimming seperate that's what you will need.
https://www.rapidled.com/cased-potentiometer-with-knob/

I just ordered one....
https://www.amazon.com/Aluoflower-C...8&qid=1528664972&sr=8-1&keywords=3590S-2-104L

I have some concerns about shortening the day length like you plan. With only 10h but higher intensity, you maybe have the same DLI, but shorten the daylength has also an impact on phenotpys and ripening for instance.
As far as I know, a shorter daylength cause that the plants are finishing faster ... Sometimes by a week or more! How a plant response should be also strain dependent. A short flowering indika profits probably much less than a 12-14 week sativa.
We've had someone here once before who claimed to use 6h cycles with doubled intensity. But it turned out, everything was just useless blah blah... He suddenly stopped posting anything, lol!
You can try it, it probably works well with some strains. But I'm almost sure that sometimes the opposite will be the case. 12/12h rhythms have not been established as indoor standard daylength for best results for nothing.

For instance in jamaica they usually have a summer and a winter grow(13h vs. 11h daylength). Sometimes the plants not only show a totally different phenotyp than in the summer it yielded much less because it finished much earlier. Okay, that strain I'm talking about is fully adapted to the location but it shows in which direction it goes.

It is for sure an interesting project and it seems you know what you are doing. I'll definately follow the thread to see how it goes.

Randomblame said:

We've had someone here once before who claimed to use 6h cycles with doubled intensity. But it turned out, everything was just useless blah blah...

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I think that's where I picked up the idea to try it with 10 hours. The heads up is appreciated. It makes sense that messing with the hours of light exposure would also mess with a plant's genetic expression.

So does anybody know which driver to use to power 22 Samsung LT-Q562A strips? They have a min Vdc of 20.8 typical Vdc 21.9 and 23.1 Max Vdc. I was looking at the HLG-240h line and neither the -20 or -24 seem to work as neither supports the complete voltage range of the strips. The same problem happens with the 320 line as well with the HLG-320h-24 having a bottom end of 21Vdc. It would seem that the HLG-480h-24 would work as it has a range of 20.4Vdc to 25.2Vdc, but it would be inefficient because the HLG-480h reaches max efficiency at around 330W, yet that's only 2% more in efficiency so maybe its a case of trying to chase that metric too far?

TaxesR4Loserz said:

So does anybody know which driver to use to power 22 Samsung LT-Q562A strips? They have a min Vdc of 20.8 typical Vdc 21.9 and 23.1 Max Vdc. I was looking at the HLG-240h line and neither the -20 or -24 seem to work as neither supports the complete voltage range of the strips. The same problem happens with the 320 line as well with the HLG-320h-24 having a bottom end of 21Vdc. It would seem that the HLG-480h-24 would work as it has a range of 20.4Vdc to 25.2Vdc, but it would be inefficient because the HLG-480h reaches max efficiency at around 330W, yet that's only 2% more in efficiency so maybe its a case of trying to chase that metric too far?

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I'm using a Mean Well HLG320H-24A with 3000K Q-strips with much success. Watts at wall is 375 with 22 strips.

Get the HLG-240H-20A. That minimum voltage can be even lower at half current. The min./max. voltage in the datasheet is at nom. current but different Tcase temps(25° means voltage can be as high as 23,1v and 90°C means as low as 20,8v) Typ. is corresponding to the 55°C mentioned as tpy. case temps.

If you dimm the strip to let's say half nom. current, the min. would be probably 20,3v and max. maybe 22,6v. There are charts further down in the datasheet which shows what temps at what current and how the voltage shifts depending on temperatures.

It depends on how much strips you connect in parallel. Is the current(driver current thru number of strips) each strip gets lower as in the datasheet the voltage would be lower too. But on the other hand cooler case temps leads to a higher forward voltage. Therefor the charts in the datasheets.

Since I'm going to be running a lot of board in parallel I was thinking about using this box https://www.digikey.com/scripts/DkSearch/dksus.dll?Detail&itemSeq=263475743&uq=636644077762585632 . I can't decipher from the technical drawing if each terminal end is isolated or if they conduct electricity to each terminals direct opposite pair.

The link doesn't work. For some unknow reason it shows only the search page.
To wire a number of strips in parallel you could use terminal blocks and bridge strips like this:

https://www.ebay.com/itm/Terminal-b...543952?hash=item2cd4d8e010:g:aCgAAOSwIedbAvWd