Hey THC-farmers! I'm looking to upgrade my 600w HPS to three qb96s. I am hoping to find someone here who has experience with these and can guide my new setup. I'm using a 3'x3' tent, and I'm looking to power these at a low wattage. I've read 30-40w per square foot is a good target for quality LEDs. So 270w to 360w for a 3x3 tent.
Max power rating with passive heatsink cooling is 4.2A at around 56V = about 235w. I've read, however, that many people will provide active cooling after 120-150w.
I am thinking about running three qb96s in parallel with a meanwell 320H-54B. The meanwell driver is rated up to 6.0A, so each board would recieve about 2.0A of current at 53v for a total of about 106w per board. I've read that the meanwell boards push past their voltage rating, but I'm not sure this is true of their amperage rating too.
At 53v the boards have an efficency of 2.4 μmoles/joule. If my math is right, 106w should generate 254ppf per board for a total of 762ppf. Then if I divide this my by the square meter space (i.e. 3x3 = .9m x .9m) I can figure a ppfd of 911 (762ppf/.836sqm). So at max power I can hope for a 911ppfd during flowering.
As a follow up to this math a poster called Or_Gro on a couple of other cannabis forums provided some light testing results of these fixtures:
Here he runs three qb96s with a meanwell 240h-54a in a 4x4. At 120w within a 3'x3' space he measures 400-800ppfd, very close to what the math predicts. My idea, rather than use three 240H-54a drivers, is to use one 320H-54b driver and run these fixtures in parallel at around 106w each.
What do you think? Is this going to be enough light for a decent yielding, high quality grow in a 3x3?
Im sure there will be lots of support for the boards but i dont think you can match a 600 hps with the low power boards regardless of the nice light spread.
Im sure there will be lots of support for the boards but i dont think you can match a 600 hps with the low power boards regardless of the nice light spread.
Hey MIMedGrower! I am in MI too! And I hear you, my main concern is I am underpowering these. What do you think about the general recommendation of 30-40w per squarefoot for LED tech? There is a meanwell 480H-54 driver that would allow me to run each board around 162w for a total of 480w. It's just $50 more expensive.
Hey MIMedGrower! I am in MI too! And I hear you, my main concern is I am underpowering these. What do you think about the general recommendation of 30-40w per squarefoot for LED tech? There is a meanwell 480H-54 driver that would allow me to run each board around 162w for a total of 480w. It's just $50 more expensive.
No worries! Thanks for stopping by anyway. I just finished my 2nd grow with a MH and HPS. I've done two other grows with blurple LEDs too. I guess at this point, I'm tired of the higher energy costs of HIDs, and I'm hoping I can make a setup that's energy efficient and can still boast good yields and quality. I've read many people raving about cmh bulbs, and I wish I started there instead of MH and HPS.
No worries! Thanks for stopping by anyway. I just finished my 2nd grow with a MH and HPS. I've done two other grows with blurple LEDs too. I guess at this point, I'm tired of the higher energy costs of HIDs, and I'm hoping I can make a setup that's energy efficient and can still boast good yields and quality. I've read many people raving about cmh bulbs, and I wish I started there instead of MH and HPS.
I realized yesterday my math was wrong, and I am confused. Oops!
I don't think calculating these boards' ppfd is as easy as multiplying their corresponding efficiency (i.e. umol/joule) by its power draw (e.g. 106w. Perhaps that will calculate their true ppfd, when the plant is directly against the board. But the plants often are at some distance away.
My next guess is the ppfd value can be adjusted using the inverse square law. Back to the drawing board!
My best resource for now is Or_Gro's work measuring ppfd at 18". So I owe thanks to Or_Gro. 160w per board seems to put out an intensity greater than my 600w hps, so I think I'll go that direction.
If anyone out there could offer advice or guidence on their qb96s it'd be greatly appreciated.
I realized yesterday my math was wrong, and I am confused. Oops!
I don't think calculating these boards' ppfd is as easy as multiplying their corresponding efficiency (i.e. umol/joule) by its power draw (e.g. 106w. Perhaps that will calculate their true ppfd, when the plant is directly against the board. But the plants often are at some distance away.
My next guess is the ppfd value can be adjusted using the inverse square law. Back to the drawing board!
My best resource for now is Or_Gro's work measuring ppfd at 18". So I owe thanks to Or_Gro. 160w per board seems to put out an intensity greater than my 600w hps, so I think I'll go that direction.
If anyone out there could offer advice or guidence on their qb96s it'd be greatly appreciated.
This my thought for White lights in GENERAL. 45-60 watts true per sq ft..I currently run a mix of (in the flower tent) older QBs and a newer mix of Kingbrite (HLG knockoffs) + a single higher end Unitfarm UFO80 (Cree and Oshram diodes (burple( ) .
I run about 70 watts per sq ft QBs and Kingbrites are dimmable
Of course you can mix in other lights and get the power that you want.
I like the reports on the new Elites, but for me..too much $$.
I say more is better since you can dim them to the value that you wish.