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Two 315w cmh or one 630w cmh?

xBluex

xBluex

New member
Hi so I have a 4x4x6 grow tent on the way and I am going to be using cmh grow lights but I want to know if the good folk at grow weed easy thinks it’s better have two 315w cmh grow lights or one 630w grow light? I’m just needing opinions on the effectiveness of two 315 cmh lights vs one 630w, not so much on power consumption or the heat it gives off. Thank you in advance.
 
I would go with one 630 so you don’t get that overlapping hot spot in the middle of the lights ppf footprint. More evenly distributed footprint of par and ppf
 
Oh ok thank you, yeah come to think of it I can see how the two would over lap in the middle, didn’t think of that. At first I was thinking two would better as you could cover more area but that makes sense. Thanx again.
 
Nice thing about two is if you have trouble with one light you can still keep going till you get it fixed don't worry about the over lap
 
I did look into the 315 & 630 lec at one point and recall the btu's for a 315 was around 1,200 btu's and the 630 lec was 2,500 btu's.
The difference was very slight-

Check the manufactures information for the brand you are looking at.

I'm an LED grower and pay extra attention to btu's.
Using the lights on/off-grow/bloom-switches from multiple lights makes it easier to control heat.
 
Please explain its a 4x4 tent ⛺️. How would you get better coverage when to the end of your walls is 2 feet off center. And how would you deal with the hot spot with two lec. I’m interested how YOU would do it. So please fill me in with why you would 2 lecs and have two hoods in a 4x4 area.
 
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It’s been humid today how are you doing it I rember your in the same county as me. I love my new leds much better heat dispersion. I made the change because growing in a 3rd story come middle of August is going to be fun.
 
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I switch from auto flowers to photo for the summer.
That way I have lights out from 10am to 4pm during the hottest part of the day.
I will switch to flower 12/12 around July 4th for grow completion around Labor Day.
Then back to autos @ 20/4 & 24/0
 
Yeah i have never tried autos. But it reminds me of how Monsanto took Corn and Genetically engineered to not give off seeds so every year the farmers have to buy new seeds from monstanto and the idea of that is just ugh... Plus i love cutting clones and not having to buy seeds.

But it may be something i try down the line just to check it out. But im starting to learn if things are working the way you are doing it dont change it lol. Thats always my biggest problem is i always try to do something better instead of being content in my grow i always want to improve it. Its been an up and down though but i have learned alot along the way. I always journal any useful information i find that way i have it for future re fence or and tips and tricks i learn.

Its cold as fuck today though ehh. You ever go to greenlife garden planet?

I wish i did my timer different but i didn't but im finding my grow room is easy to keep cool my flower hasnt gone over 75 degrees since they got switched. I was going to do my Flower 5pm to 5am and the veg 5pm to 11am. So i miss the hottest part of the day in the room but with the leds i have no problem with heat anymore after switching from 600 mh/hps running both at the same time. I also had setup a poor ventilation system.
 
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Hey 88, I'm no light expert and don't claim to be, and when I read all that ppfd, stuff I get a bad headache, so I don't read up on it.If I was alot younger I might read more.
But my 315cmh doesn't have a hot spot that I know of.
And xBluex, said he wasn't worried about the heat, if I recall.
But I would still say 2-315s ,would cover a 4x4 better than 1-630, cause I think I remember asking GrowersChoice that same question, But I'm not positive. And I been wrong about a bunch of stuff.
But I bet DANGERDAN knows,
 
Yeah agree'd. I dont know about LEC much but i know leds overlapping can give you a hot spot. I didn't know about PPF/PAR till about 2 months ago. I learned LUMENS was the measurement of light from THE GROW BOSS on youtube but the video has since been deleted i wonder why lol.

The PPF stuff is very interesting if you do get reading into though. I have been stuck for hours reading it lol that and light specs and reviews on amazon ETC.

I was just interested in how you would setup 2 lecs in a 4x4 tent.

Lol its always a learning experience i can't count the times i have been wrong but my yield some grows reflected it! So when that happened i LEARNED how not to grow marijuana.
 
D.A.A.S.69 Inuart88

Ignoring whether two 315s would fit in a 4x4, spreading light over more surface area improves uniformity and reduces hotspots. Although you may get overlapping with two fixtures due to superposition, you get the same problem with a single fixture. But more severe hotspots due to the higher concentration of energy in a confined area.
 
Thank you all and shout out to D.A.A.S, yeah I was thinking that would get better coverage, as for the middle part of over lapping if just keep the plants away from
the middle, mainly tucked away on the sides one in front of the other or at least keep a gap somewhere in between. Quality over quantity Is how I’d want it.
 
Thanks DANGERDAN, my light came from GrowersChoice, it's kinda small, but I can fit 2 lights, like mine in my tent easily, but they said it was perfect for my size tent.
Thanks again DangerDan.
 
I was really meh about CMH at one stage, but i believe its a great technology for the beginner grower. Its only downside is its short lifespan due to it being a metal halide relative.
 
Mine came with a 3year warranty, plus I got a 3000k, and a 10k finishing bulb for free, and I'm sticking with my 315, for 2 more years anyway. lol
 
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