Advice on QB wattage for 2x4 DWC tent

Hey all, hoping someone with more knowledge in the QB realm can help out here.
What I'm running:
-2x4x6 foot tent
-3x 5gal DWC with premium feminized genetics
-RH stable at 65-70% (shitloads of air, res temps at 70f max, keeping rot at bay with UC roots and hydroguard (not at the same time if course))
-air temp stable at 82f with my current 400w (actual draw) veg LED
-co2 stable at 800-900ppm, to be increased as needed
-training for 8 cola mainlines

So my question is: would a 480w QB w/Samsung lm301b be Overkill, assuming co2/temp/rh can be set to match light intensity? I'm planning on buying either a 480w (similar to hlg 550 v2) or a 260w (like the spider farmer 2000w..) I'll also be supplementing with a uv a/b tube, but I'm concerned the 480w might be too much. However from the ppfd/par charts it seems the 480w is the only light that could give me 1000+ ppfd over the entire cannopy, which will be roughly 2x3 or 3.5.

Any thoughts?

Thanks

The 550 would do work in there

A 480 would be a little over kill but you could always dim it. But for a 2x4 I would get two 260w QB’s for better coverage since you want more of a rectangle. Care to link the spider farmer light you’re looking at?

Im running 4 qb288 v1 @ 60w each (hlg240h-c1050) over a 2x4. Better spread and efficiency. Im getting 900-1000ppfd across all my tops no problem, with half the wattage.

Mikenike said:

A 480 would be a little over kill but you could always dim it. But for a 2x4 I would get two 260w QB’s for better coverage since you want more of a rectangle. Care to link the spider farmer light you’re looking at?

Click to expand...

Spider Farmer SF-2000 LED Grow Light with Samsung Chips LM301B & Dimmable MeanWell Driver Commercial White Grow Lights for Indoor Plants Full Spectrum for Greenhouse Hydroponic Veg Flower 606pcs LEDs https://www.amazon.com/dp/B07TVD1Y3K/ref=cm_sw_r_cp_apa_i_5utzEbEZNH80Z

Thanks for the advice. Spider farmer seems pretty decent but I'd hate to dish out $600 for 2 if I can get all I need for 3 plants with a 480w for $340. Although that does mean if I expand to a 4th plant and actually fill my space id probably want a second one anyway.

Djgrundleswick said:

Spider Farmer SF-2000 LED Grow Light with Samsung Chips LM301B & Dimmable MeanWell Driver Commercial White Grow Lights for Indoor Plants Full Spectrum for Greenhouse Hydroponic Veg Flower 606pcs LEDs https://www.amazon.com/dp/B07TVD1Y3K/ref=cm_sw_r_cp_apa_i_5utzEbEZNH80Z

Thanks for the advice. Spider farmer seems pretty decent but I'd hate to dish out $600 for 2 if I can get all I need for 3 plants with a 480w for $340. Although that does mean if I expand to a 4th plant and actually fill my space id probably want a second one anyway.

Click to expand...

Yeah sorry I was thinking your whole space. Almost always, a lot of folks fill up their tent haha I only used part of my space at first too then I wanted to fill the whole space. What 480w light you looking at? From alibaba? I’m sure you could get a 480w equivalent for roughly the same price. Like two 240w boards, if you were referring to alibaba that is.

I'd also suggest trying to get two boards that will cover 2x2 each, and then you can hang your uv bulbs along side the units. If you can afford this it will give you more flexibility/efficiency later when ''you will definitely'' up the area usage to justify the W used. It's also useful in spreading the W load across various outlets for safety, and that you won't lose all light output if one board/electric line fails for w/e reason.

It's a wise idea to have a back up light if you only have one high output source, but the expense you have for a back up that might actually never be needed, and only vaguely even if, til you get a new led.. it starts to seem more wise to just buy two low W boards that you will always use until one breaks.

Flowki said:

I'd also suggest trying to get two boards that will cover 2x2 each, and then you can hang your uv bulbs along side the units. If you can afford this it will give you more flexibility/efficiency later when ''you will definitely'' up the area usage to justify the W used. It's also useful in spreading the W load across various outlets for safety, and that you won't lose all light output if one board/electric line fails for w/e reason.

It's a wise idea to have a back up light if you only have one high output source, but the expense you have for a back up that might actually never be needed, and only vaguely even if, til you get a new led.. it starts to seem more wise to just buy two low W boards that you will always use until one breaks.

Click to expand...

Thanks for the advice. My current led can serve as a backup (it does have a Bloom switch and for a blurple light it actually puts out a decent ppfd reading). I'm thinking I'm going to push this to the extreme and start with one 480w then add another when I'm ready to fill my space.. with two of these: ttps://www.amazon.com/dp/B0817D5D6K/ref=cm_sw_r_cp_apa_i_7lvzEbQY715D7 basically the entire ceiling of the tent will will puting out light. 1000+ ppfd at all points of co2 enriched, mainlined/super cropped dwc with some of humboldt's best genetics. Should be absurd yield and bud size, assuming all other conditions remain optimal.

Djgrundleswick said:

Thanks for the advice. My current led can serve as a backup (it does have a Bloom switch and for a blurple light it actually puts out a decent ppfd reading). I'm thinking I'm going to push this to the extreme and start with one 480w then add another when I'm ready to fill my space.. with two of these: ttps://www.amazon.com/dp/B0817D5D6K/ref=cm_sw_r_cp_apa_i_7lvzEbQY715D7 basically the entire ceiling of the tent will will puting out light. 1000+ ppfd at all points of co2 enriched, mainlined/super cropped dwc with some of humboldt's best genetics. Should be absurd yield and bud size, assuming all other conditions remain optimal.

Click to expand...

I think you are going to have heat issues with one, let alone 2 of those units in a 2x4.

Also from everything I have read, even with co2, anything more than 40 w/sf is going to be wasted. 480w would be 60w/sf. I could be wrong but it seems like you are trying to use equivalent HPS/CMH wattage requirements instead of looking at the end result of photons that actually reach your plant.

If you really want the highest efficiency build I can think of for that space and money is of no concern, build a setup like mine but run 5 V2 Rspec boards in series on an HLG 320W driver. Look at the spec sheets and see how much more light you get running them softer. They also put out less heat and let you drop them closer to your canopy this way. You would still be at 40 w sf as well.

Djgrundleswick said:

Thanks for the advice. My current led can serve as a backup (it does have a Bloom switch and for a blurple light it actually puts out a decent ppfd reading). I'm thinking I'm going to push this to the extreme and start with one 480w then add another when I'm ready to fill my space.. with two of these: ttps://www.amazon.com/dp/B0817D5D6K/ref=cm_sw_r_cp_apa_i_7lvzEbQY715D7 basically the entire ceiling of the tent will will puting out light. 1000+ ppfd at all points of co2 enriched, mainlined/super cropped dwc with some of humboldt's best genetics. Should be absurd yield and bud size, assuming all other conditions remain optimal.

Click to expand...

I would echo the above post but from another angle. You have to consider the tent is very narrow giving high levels of reflection, you may well top out the light height and still see light stress depending on plant heights. In a CO2 sealed environment you are going to need good internal cooling to stop such a small space quickly over heating under that W. Humidity > condensation may also become a nightmare and a danger.. and is something you might not be able to get under control logistically. I would say tread carefully with such a setup and make sure you understand the requirements and only buy decent gear. If for example your cooling system bugs out, 1k W in that space is going to be a fire or condensation shock hazard. Now people might say bah, the risk is minimal given today's fuse systems and build quality's.. but the golden rules always apply. Water/heat/electricity is a dangerous mix, especially in a confined space.

I'm not trying to put you off, but do be sure to research these issues to the point you are sure I am simply paranoid.