DIY QB96 driver advice and options

@Rocket Soul that's interesting, I did not know that. Well that'll certainly make life easier keeping temps "down"? VPD, not gonna lie, had to look that up: "Vapor Pressure Deficit" ...and you are saying that the lower leaf temperatures reducing the VPD are not the only thing at work? Like spectrum effects the needed room temperature as well?

(I'm going to be doing some looking into VPD as it applies to all this, havent read much yet. I'm pretty much jumping in head first in order to fit personal timetables. Spotted this active one on the topic your in: https://www.rollitup.org/t/led-and-room-temp.999465/)

@GBAUTO Same deal, that's a higher temp than I expected.

Does this mean you both are around 70-80% humidity to be on the VPD chart or that the chart shifts significantly for LEDs and you've got lower humidities? Mind if I ask your day/night humidities?

PS: The further down the rabbit hole I go the more turtles I find e.g. (https://www.rollitup.org/t/led-and-room-temp.999465/)

Thanks so much! I will move on over to my own thread soon here. I plan on making a journal and could start with the setup. That being said @XtraGood my 4x4 HPS tent is over an hour away from where I live. So while I just finished up those northern I included with pics I will be letting my brother in law start using/learning HPS with my setup and I'll take a 1/3rd cut from his crop.

This is actually the reason I am hashing out the details for this closet grow. I want to make it as close to a tent environment as possible as for a first time grow I like to think I had pretty good success.

It won't tag @HolyAngel for some reason maybe because I am in mobile. However thank you so much for that info. So 380 watts should be just about perfect for my space? In order to get that 380 watts you recommend 2 options which I was at first looking at those 288s. However I will be vegging in this setup as well and the 96s run close to 3500k spectrum so that added blue in my research has grown much quality bud. I think I'm stuck on those 96 elites. And they are 69.99 including the "good" heat sinks right the ones that comes with them on the HLG site? So the driver you recommend if I use 3 96s is the 600? I think that is doable I will have to price that driver. I have no problem adding 120 or 140 PC fans if I had to. I'll check back here when I get home off mobile and elaborate a bit then hopefully place my order. You all rock so much thank you for the quick and educating responses! This is all new to me and extremely fun however one can get lost for months in research and I want to get growing.

EDIT : OUF that HLG-600H-54 A costs alot of money heh. I may have to bring that cost down some if I can still get the required 380ish watts somehow with a diff driver.

KilleN said:

Thanks so much! I will move on over to my own thread soon here. I plan on making a journal and could start with the setup. That being said @XtraGood my 4x4 HPS tent is over an hour away from where I live. So while I just finished up those northern I included with pics I will be letting my brother in law start using/learning HPS with my setup and I'll take a 1/3rd cut from his crop.

This is actually the reason I am hashing out the details for this closet grow. I want to make it as close to a tent environment as possible as for a first time grow I like to think I had pretty good success.

It won't tag @HolyAngel for some reason maybe because I am in mobile. However thank you so much for that info. So 380 watts should be just about perfect for my space? In order to get that 380 watts you reccomend 2 options which I was at first looking at those 288s. However I will be vegging in this setup as well and the 96s run close to 3500k spectrum so that added blue in my research has grown much quality bud. I think I'm stuck on thise 96 elites. And they are 69.99 including the "good" heatsinks right the ones that comes with them on the HLG site? So the driver you reccomend if I use 3 96s is the 600? I think that is doable I will have to price that driver. I have no problem adding 120 or 140 PC fans if I had to. I'll check back here when I get home off mobile and elaborate a bit then hopefully place my order. You all rock so much thank you for the quick and educating responses! This is all new to me and extremely fun however one can get lost for months in research and I want to get growing.

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The qb288 v2 rspecs are the same 3500K rating as the 96 v2's last I checked.. but the 288's don't come with heatsinks for that cheap.

Yes that $69 96v2 board with heatsink is the correct one. And yeah the hlg 600 will drive 3x 96's at 2/3 power each which will likely be overkill for that space but will give you room to grow

XtraGood said:

@Rocket Soul that's interesting, I did not know that. Well that'll certainly make life easier keeping temps "down"? VPD, not gonna lie, had to look that up: "Vapor Pressure Deficit" ...and you are saying that the lower leaf temperatures reducing the VPD are not the only thing at work? Like spectrum effects the needed room temperature as well?

(I'm going to be doing some looking into VPD as it applies to all this, havent read much yet. I'm pretty much jumping in head first in order to fit personal timetables. Spotted this active one on the topic your in: https://www.rollitup.org/t/led-and-room-temp.999465/)

@GBAUTO Same deal, that's a higher temp than I expected.

Does this mean you both are around 70-80% humidity to be on the VPD chart or that the chart shifts significantly for LEDs and you've got lower humidities? Mind if I ask your day/night humidities?

PS: The further down the rabbit hole I go the more turtles I find e.g. (https://www.rollitup.org/t/led-and-room-temp.999465/)

Click to expand...

Yeah this is definitely what I've been told too, 81-86 for these LEDs and upper end of RH but I haven't tried it myself. Closest I've gone so far is 76F and ~60% RH and they're loving it. I'll know more here in a couple weeks when I switch to flower.

@HolyAngel https://horticulturelightinggroup.com/collections/all/products/qb288-v2-with-slate-2-triple with this https://www.digikey.com/product-detail/en/mean-well-usa-inc/HLG-480H-54A/1866-2554-ND/7704117 roughly 420 for this?

Or https://horticulturelightinggroup.com/collections/all/products/qb96-elite-v2-quantum-board-engine with https://www.mouser.com/ProductDetail/MEAN-WELL/HLG-600H-54A?qs=5pLaOnqdcwP1hbZPnj5WVA== ? roughly 390ish for this?

Both are in my price range, albeit the top end, though I didnt calculate in shipping yet so maybe it is a tiny bit too rich for my blood. heh

Also is it doable to achieve the same 360-380w with just 2 of either of those lights? ( I do like the idea of not needing active cooling, your saying both of those options you listed will run passively cooled with the heatsinks?

KilleN said:

@HolyAngel https://horticulturelightinggroup.com/collections/all/products/qb288-v2-with-slate-2-triple with this https://www.digikey.com/product-detail/en/mean-well-usa-inc/HLG-480H-54A/1866-2554-ND/7704117 roughly 420 for this?

Or https://horticulturelightinggroup.com/collections/all/products/qb96-elite-v2-quantum-board-engine with https://www.mouser.com/ProductDetail/MEAN-WELL/HLG-600H-54A?qs=5pLaOnqdcwP1hbZPnj5WVA== ? roughly 390ish for this?

Both are in my price range, albeit the top end, though I didnt calculate in shipping yet so maybe it is a tiny bit too rich for my blood. heh

Also is it doable to achieve the same 360-380w with just 2 of either of those lights? ( I do like the idea of not needing active cooling, your saying both of those options you listed will run passively cooled with the heatsinks?

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yeah pretty much both passive. 3x 96 w/600 won't need fans, and 3x 288 rspecs on the 320 won't need fans. If you do the 288's with the 480H you may want fans when they're maxed.

You could just buy two for now and get a 3rd later when you're ready. My two qb288 v2 rspecs are running off an HLG-320H and can pull 375 watts at the wall when the IO pot on the driver is turned all the way up. Each driver is different tho, all are guaranteed to hit 320 on the 320H but anything above that is a guess what it'll do. If you did get only two boards with either the 480 or 600H drivers you will want to turn that pot down a bit before powering.

So I just bought 2 of the qb96 elite v2s . I do plan on maybe getting another one or some other goodies to maximize the grow space but can I get the most out of this 10 or so square feet with 2 qb96s? Will the spread be enough?

Also should I still get the 600h? Or can I/should i get the 185 or 240 and max them out at .. what 200watt each? To get my required 380w in the space. I haven't ordered any drivers yet.

This is where I get a bit confused. Heh is it best to run a larger driver and wire them series or parallel [what is the advantage to both ?] So many options heh. Not sure the most effective way to go about this currently.

P.S. totally sorry for hijacking your thread, at this point it seems redundant to start a new thread when most of the answers are in this one. Hopefully my questions help others so there is that.

@KilleN
Actually looking at your space again.. If it's 1.75 by 6, and each qb96v2 covers 3x3, that's two 1.75x3 area's to cover, or 185 watts per sqft. HLG sells their dual qb96 setup with basically a 320H driver and it covers a 3x3 or 2x4 area. Your's will be spread apart more but I think it'd work for awhile until you can get another 1 later. For drivers you could either do two HLG-185-54A's, 1 per board, and get a third later for the 3rd 96v2. Or you could do what I'd really recommend and get just one HLG-320H for the pair and wire them in series, this would be roughly the same as the two 185's. That same driver will also run 3 boards.

So I'm reading about VPD, how do the higher temperatures and humidities under LEDs play into pest management. I'm specifically wondering about Powdery Mildew? Worse under LEDs?

You have to keep the difference between night and day temps low, higher temps at night. you have to manage your cannopy to not have too much leaves touching, lolipop, more airflow etc
Make sure your extraction is on point when lights out. But mainly maintaining temps, pm will only start if you have high rh and low temps.

Also, vpd is guide lines not strict rules. Most people will lower rh towards the end of flower anyway.

Still recovering from this VPD info assimilation, it would be nice if there was a spread sheet with the different leaf temperature delta's as sheets.

I don't have a good way to measure leaf temperature difference from air yet (IR temp gun on the way), what is the normal range people see under LEDs or these QB96's specifically, I have seen a few things searching around but not much. 1-2 degrees C with LEDs? With HIDs its 4-5 degrees C?

Built a pond fogger humidifier with WH8040 controller. Venting is going to be interesting to see what happens with the humidity. Hoping there aren't any hidden pitfalls to doing pond foggers.

Edit: My driver order got kicked back over the holidays, so I got a bunch of HLG-185H-54A's, (2) HBG-200-60A's, and a few HLG-320-54's instead.

@XtraGood
Have you looked at this site?

They have a calc, and a chart and some other info.

Yeah the 185's would be the way to go, 1 of those drivers per board will do ya fine. And switching to a 320 later would either let you run two boards per driver, or be able to max one board out if you did 1 per driver, although the A driver's(e.g. 54A) will be limited on the amount they can dim. A 'B' driver and a potentiometer would let you have the full range of dimming available. Just a thought.

That calculator gives different answers than this one unless I'm messing it up on the first pass: https://vpdcalculator.com/vpd-calculator

Nice that they've got charts for 0-5 degrees of leaf temp differentials there.

Got my first qb96 wired to a hlg-185-54 and it certainly makes light. IR gun says ~65 C on the board after 5-10 minutes, I'll leave it on longer tomorrow.

Looking for advice on a light meter to compare different LED lights with, searching around at the moment and it looks complicated.

well.. You can get some lux meters cheap or use your smartphone, hlg provides a constant you can use to calculate ppfd based on lux.


The best option would be to get an apogee par meter, something like the mq-501, but those things are like ~$500

Anything around $100 that's in common usage on the various forums? (So that I can do easy estimated comparisons of lights. (my phone is very old ))

I played with the dimming a bit and with voltage topped and current restricted to 185 at the wall on a kill-a-watt meter and time to stabilize, my IR gun's (-50 to 380C range) max reading at the light was 95C, 10C over whats recommended on the sales page. That's in a still room with low RH. Pointing a fan at it from 5ft away on low brings it down about 10C. The HLG-185a-54 was drawing almost 270 watts at the wall when both voltage and current are maxed out, I was not interested enough to let it run that way for long though, temps were on the way up, I saw 105C.

That should allow me to set mine to 54a and get about 200w easy enough with my hlg-240h-54a right? I dont have any way to measure my actual wattage atm

KilleN said:

That should allow me to set mine to 54a and get about 200w easy enough with my hlg-240h-54a right? I dont have any way to measure my actual wattage atm

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You should be able to get quite a bit more than 200w from that driver.

What's a worth while set of eye protection to go along with these qb96s? I'll pay extra for something better when it comes to eye protection, looking for good/appropriate options.