Lighting help for 3x3 closet grow.
- Thread starter goldenbudzz
- Start date
PadawanWarrior
Well-Known Member
You're getting some bad advice from most of these nubes if you ask me. A 315 CMH would be perfect. If you want LED it depends on your budget. Or even a 400 watt HPS/MH setup if you wanna something cheaper.
Or listen to the new guys.
bernie344
Well-Known Member
I have no time for trolling, welcome to my ignore list.
PadawanWarrior
Well-Known Member
Doug Dawson
Well-Known Member
Wow. Please put me on it too. I don't want to waste your time.
Henchman2one
Active Member
Plant # is calculated from grow area.
4ft2 per plant is typical for traditional grows, gives em a bit of room to grow into. With a 4/5wk veg, the plant will roughly take up about 4ft2 (more or less) by harvest time. A 4×4 tent = 16ft2 = 4 plants.
Watts tell you how big your grow area will be. 240W ÷ 30W/ft2 = 8ft2. So a 240W light will be enough for about ~8ft2, or 2 plants that consume 4ft2 each, or 8 plants that consume 1ft2 each or 16 plants that consume 0.5ft2 each. Typically I go for 4ft2 per plant, but some use different spacing ect, but your wattage will only tell you how big your area can be. Plant # can be anything you desire as long as your wattage/ft2 is right.
4ft2 per plant is typical for traditional grows, gives em a bit of room to grow into. With a 4/5wk veg, the plant will roughly take up about 4ft2 (more or less) by harvest time. A 4×4 tent = 16ft2 = 4 plants.
Watts tell you how big your grow area will be. 240W ÷ 30W/ft2 = 8ft2. So a 240W light will be enough for about ~8ft2, or 2 plants that consume 4ft2 each, or 8 plants that consume 1ft2 each or 16 plants that consume 0.5ft2 each. Typically I go for 4ft2 per plant, but some use different spacing ect, but your wattage will only tell you how big your area can be. Plant # can be anything you desire as long as your wattage/ft2 is right.
Henchman2one
Active Member
Ya nothing wrong with CMH. It's not as efficient, and will create more heat, but a pretty good wide spectrum. If you're in a tight area it will result in greater temps than equivalent wattage LED. I'd not mess with the MH/HPS combo as it's just more stuff to essentially create a CMH SPD. To be fair, there's uses for each type of light, so idk if I'd really say 1 is better than the other.
Happy trolling
PadawanWarrior
Well-Known Member
Hahaha. I hope you know I wasn't referring to you, lol. You were one of the ones with good advice. You might be one of the new ones here, but you seem to know your shit.Ya nothing wrong with CMH. It's not as efficient, and will create more heat, but a pretty good wide spectrum. If you're in a tight area it will result in greater temps than equivalent wattage LED. I'd not mess with the MH/HPS combo as it's just more stuff to essentially create a CMH SPD. To be fair, there's uses for each type of light, so idk if I'd really say 1 is better than the other.
Happy trolling
But that 260 KingBrite is an odd size for a 3x3 if you ask me.
Henchman2one
Active Member
Haha well we all get a lil froggy from time to time.
The KB should be decent. Lets say it's 2.5μmol/J.
240W × 2.5μmol/J = 600μmol
600μmol ÷ 9ft2 = 66.7μmol/ft2
66.7μmol/ft2 × 10.76ft2/m2 = 718μmol/m2
Not going to fry em unless he drops the light super low, but should still have enough uumf to have a nice harvest.
A 315 has a much more solar-esque spectrum, but its only about 1.6μmol/J on the high end (I think?).
1.6μmol/J × 315W = 504μmol
504μmol ÷ 9ft2 = 56μmol/ft2
56μmol/ft2 × 10.76ft2/m2 = 602μmol/m2
They aren't the same spectrum so the plants will respond differently, but the width in SPD of the CMH is maybe offset by the increase in the LED's intensity? I think you'd see similar dry weight yield from either light in a 9×9 (though cannibinoid ratios may differ significantly). I like the UV and IR of CMH, but perhaps temp is more important than fine tuning morpho, and maybe 75 extra watts of heat is more significant than the benefit of added morpho. Idk? At some point it becomes personal preference imo. Either light should perform well I'd imagine.
Edit-
There's some CMH figures near the bottom
Last edited:
PadawanWarrior
Well-Known Member
4 of these and a driver would be sweet too.
HLG QB96 Elite V2 High Intensity Grow Light Engine (horticulturelightinggroup.com)
If you want any amount of production in a 3x3 you are going to want 600watts HPS or 300/400watts of a quality led.
I have ran 400watt HPS in 3x3. It worked for sure but was definitely lacking. 2x 400watt in one hood rocked pretty well
I then switched to 400watts of vero29 cobs from timber. They did really well. I still run this setup. But have added side lighting for trying a different type of training.
lights genetics and water. 3 things to not cheap out on
I have ran 400watt HPS in 3x3. It worked for sure but was definitely lacking. 2x 400watt in one hood rocked pretty well
I then switched to 400watts of vero29 cobs from timber. They did really well. I still run this setup. But have added side lighting for trying a different type of training.
lights genetics and water. 3 things to not cheap out on
goldenbudzz
Well-Known Member
I’ve ran HPS/MH at my old house with a bigger tent but with this mall of space I have very few options and trying to be as efficient as possible and definitely not have to worry about heat. This will legit be in a closet thats about 3x3 max. Money isn’t necessarily the issue but not trying to spend more than $200-$250 on a light if possible. Thinking I might just go with the Spider farmer SF1000, would rather have more than enough and be able to dim it down rather than be stuck with something I can’t adjust later on if needed.
bernie344
Well-Known Member
Confirmed
eastcoastmo
Well-Known Member
Sorry for the late reply mate!
With QB's the HLG series are amazing but not the cheapest. The spiderfarmers get a pretty good rap so they are a good option.
CMH are great lights but they do generate a fair bit of heat so depends really on how much airflow you can get in there.