Seeking help/input building a new led-strip lamp

I have previously been growing in a tent with a floor area of 1 m² under 8 x cxb 3590´s and 2x HLG-240H-C1750B drivers with potentiometers disconnected for max wattage and light levels.

I´m now thinking of buying a smaller flowering tent, measuring 125 x 65 x 120 cm. I have been looking at ledgardeners 3 x 3 feet builds, which rougly equals 0.81² meters, which is my new floor area.

For sure, 10 x 2 feet samsung f-series single row strips and a Mean Well HLG-320H-24B driver would grow great herbs. But I fear this is to little wattage. My cob-rig yields great with rock hard nugs and I think this has a lot to do with the high light levels I get with 500 watts of light.

When I built my cob-lamp one year ago, almost everyone told me to go with two HLG-185H-C1400B drivers for my floor area because that would be enough. But still, I am certain that some of the strains I have tried could have taken even more than the 480-500 watts I use now.

Would it be possible to use a larger driver or two smaller drivers with a higher strip number so I can reach about 400 watts? I would rather overdo my new lamp and dim it down if necessary than building a to small lamp.

Any input and help is most appreciated.

Just curious, but have you tried a full grow at lower wattage? Though there are some here that grow at high light levels, most folks seem to settle at around 30w/sq ft. It's possible that you could get results that are just as good, but with less power. Though I do understand your desire to over-build - my fixtures are capable of up to 40w/sq ft in my grow spaces, but running them that high stresses my plants (I believe that's partly strain-dependent though).

Yes, I had to run lower wattage when I did a run with two cultivars in one tent. One of the strains was slow growing, didn´t accept high EC or high light levels. So I probably dimmed the light to 70-90% capacity to avoid scorching/bleaching.

I cloned the other strain and disconnected the potentiometers because of the light flickering slightly because of the pot beeing defective. This strain didn´t bleach and grew like a champ. Took high levels of nutrients and all the light. But yes, the center of the light has a slight area where hotstpots made the tricomes evaporate on the top colas. But the plants in general didn´t appear stressed.

Here is a picture of the plants in late bloom. Far from perfect, constant overwatering because of hempy holes beeing to far up. Medium was 80% peat and 20% perlite. Cheap nutrients. But I think the high ppfd masked my mistakes.



I don´t believe in some nutrients beeing better than others, or that different grow-mediums(peat, coco, rockwool etc.) really matter much at all. But I want to be able to bombard with as much light as the plants can accept. I´d rather spend some extra $$ on overdimensioning the light-machine, and have that capacity at the ready in late flower.

If im not mistaken, your space is almost 9 square feet or 1 square meter in size.

The build you mention will put you around 320 watts, which is great but you could definitely use 2 smaller hlg-240 drivers or 1 hlg-480 driver and dim from there.

I get great PPFD in my 3'x3' tent using 10 samsung 2 foot strips with an hlg-320-24b driver (about 700ppfd at 12-18").

If your plan is to run closer to 400 watts, I would recommend you run an extra 2 strips. My 10x strips at 320w are at 75% of their max current, and I wouldnt personally wanna go higher than that. 400w would pretty much put them at 100% of their max current.

skoomd- Yes, my new grow space is slightly less than 9 square feet.

1.25 x 0.65 meters = 0.8125 m²
9 square feet = 0.8361 m²

700 ppfd is efficient, and I read that if you go higher the photosynthesis becomes less effective. But power is cheap where I live, and I want hard nugs. When I watched growmau5´s record yield video on youtube, the one where he ran his 3590´s on soft current, his buds seemed to be a bit airy. Could of course be strain-dependent, or me seeing wrong, but it makes sense to me that less intensive light levels decreases quality.

I have also read that the dutch growers always tried to get as much light as possible in their grow tents and rooms to increase quality and yield. I can´t document it, but I think I have seen examples where they have crammed 1000 watts of hps into 1 m² grow tents.

Ohlson said:

skoomd- Yes, my new grow space is slightly less than 9 square feet.

1.25 x 0.65 meters = 0.8125 m²
9 square feet = 0.8361 m²

700 ppfd is efficient, and I read that if you go higher the photosynthesis becomes less effective. But power is cheap where I live, and I want hard nugs. When I watched growmau5´s record yield video on youtube, the one where he ran his 3590´s on soft current, his buds seemed to be a bit airy. Could of course be strain-dependent, or me seeing wrong, but it makes sense to me that less intensive light levels decreases quality.

I have also read that the dutch growers always tried to get as much light as possible in their grow tents and rooms to increase quality and yield. I can´t document it, but I think I have seen examples where they have crammed 1000 watts of hps into 1 m² grow tents.

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I don't know, man... More light is definitely not always better, and there is a point of diminishing returns. As for bud density - that does seem to be very strain dependent, and I haven't seen anything to indicate that a certain PPFD level determines density. And cramming 1000w of light into roughly 9 square feet sounds like a good way to beat the shit out of your plants, if that's what you're after! I'm not disputing that you got decent results, but it wouldn't hurt to do some research (on intensity) here on this sub-forum, because there are a lot of very experienced LED growers that run far less power than you're planning to. Best of luck.

My worry is that 320 watts might not be enough for all strains, and that light levels will be the inhibiting factor. Building in some extra redundancy would be great, even though it might never be used.

Shipment costs and import duties to my country are high, so my thinking is that a few extra strips or a driver of higher capacity could be sensible.

Maybe I could hook up 12-14 strips to the 320H and gain some efficiency, or just go with more juice. Will using a hlg-480 with 12 strips be okay with a potentiometer?

Ohlson said:

My worry is that 320 watts might not be enough for all strains, and that light levels will be the inhibiting factor. Building in some extra redundancy would be great, even though it might never be used.

Shipment costs and import duties to my country are high, so my thinking is that a few extra strips or a driver of higher capacity could be sensible.

Maybe I could hook up 12-14 strips to the 320H and gain some efficiency, or just go with more juice. Will using a hlg-480 with 12 strips be okay with a potentiometer?

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I do agree with what Humple is saying, though I dont have enough experience at higher PPFD levels to make a statement myself. I've grown rock hard nugs under blurple LEDs before with like 500-600 PPFD.

But if you have a little bit of extra money it wouldnt hurt if you had a bit more power and have a potentiometer in case you realize it is too much.

Using an HLG 480-24 with 12-14 strips and a potentiometer would be fine, but I do believe you'll end up having them dimmed down to 300-350 watts to not have too much light. On the bright side, you'll have more efficiency if that's the case.

The only way I think you'd benefit from 400 or so watts of the strips in your space is if you can keep your temps at 85F constantly, humidity in the 60% range constantly, and perhaps even using CO2 supplementation.

Thanks for input skoomd.

HLG 480-24 with 14 strips and a potentiometer sounds like a good plan.

Ohlson said:

Thanks for input skoomd.

HLG 480-24 with 14 strips and a potentiometer sounds like a good plan.

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Yeah, if you have the budget, it certainly doesn't hurt to over-build. But if you're going to do that, might I recommend that you consider modularity and break-down-ability in the design of your frame? You could design it in such a way that you could quickly and easily transfer it to a 4x4 (should you ever wish to bump up your space), reconfigured to spread the strips out, and not sacrifice uniformity due to a fixture sized for a 3x3.

Good luck!

I chickened out and got the HLG-320H-24B and 14 x 3500K strips. Could not justify the extra driver cost. 84$ for 320 watts vs 151$ for 480 watts.