CMH Bulbs-4200K+ 3100K bulbs in one 630w open fixture?

A

Agronut

Well-Known Member
Hi everyone, looking for some Ceramic Metal Halide advice from experienced growers using it: I’m thinking of running one 630w open fixture CMH in my 5x5 tent. Research leads me to believe that combining one Phillips Greenmaster 3100K bulb and one Eye Hortilux 4200K bulb in same fixture will cover all spectrums including UV.

Would two Phillips 3100k bulbs with a supplemental UV light (CFL like Agromax) be better? Or, what would be better in general?

Also, any thoughts on temperatures in that 5x5 tent would be appreciated....so far I didnt even need to cool with just one chinese-ebay CMH 315w, have a feeling the open fixture 630w could change that. Thanks!
 
J

Juan Duran Gorilla Grower

Active Member
I have those same questions & some.?.?..I just got my hands on a Nanolux CMH 315 with a vertical bulb type of open fixture & a non branded CMH 630 with the Gavita style horizontal bulb open fixture. All 3 bulbs are the Philips Greenmaster 3100k's.Ive been alternating between a old Black Dog LED 750,Gavita 1000,some Adjust-a-wing DE & SE 1000's. Trying different combinations in different rooms,a shed,a garage,tents 4x2,5x5, & 8x4's. Mostly with the Blue Ebb & Flow buckets in hydroton lightly trained in a SCROG. I cant seem to get out of the # a light box & keep hearing the norm should be nothing less than 2 closer to 3#'s...How do I get there?
 
coreywebster

coreywebster

Well-Known Member
Juan Duran Gorilla Grower said:
I have those same questions & some.?.?..I just got my hands on a Nanolux CMH 315 with a vertical bulb type of open fixture & a non branded CMH 630 with the Gavita style horizontal bulb open fixture. All 3 bulbs are the Philips Greenmaster 3100k's.Ive been alternating between a old Black Dog LED 750,Gavita 1000,some Adjust-a-wing DE & SE 1000's. Trying different combinations in different rooms,a shed,a garage,tents 4x2,5x5, & 8x4's. Mostly with the Blue Ebb & Flow buckets in hydroton lightly trained in a SCROG. I cant seem to get out of the # a light box & keep hearing the norm should be nothing less than 2 closer to 3#'s...How do I get there?
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To get a high yield you need the lighting, you have that bit, but you need veg time, and plant count and to fill your space. Scrog is a great way to get good numbers but trying to fill that 5x5 with one plant rather than 5 or 7 will impact your bud size and weight.
Strain is also a big factor.
Just remember you can have all the light in the world but without the rest of the variables been right you wont hit those high GPW or GPSF figures.


Also
@Agronut having the different spectrum will change the structure of the plant, internode space and bud size will vary depending on which combo you use, you may as well try two flowering bulbs and then next run try mixing the veg and flower spectrum. I would also consider doing the same in veg with the veg bubs and combo of both bulbs.
I have only flowered once with cmh but I used that 3100k bulb for veg for many grows and its an amazing veg light to be honest. The spectrum is great all round.

Regarding the temps, you should be exchanging air regardless assuming you were not adding co2. Its not just about removing the heat, its about maintaining co2 to a reasonable level, without it you are limiting your plant growth and bud production.
Its simple enough though, the heat will be twice the rise from ambient with 2 315s than it was with one, roughly, provided the cheap china light was not air cooled which I gather it wasn't or you would of mentioned it. You want a quality fan to extract.
Sorry I cant add more about the results of the bulb combos, but had to reply due to the apparent lack of air exchange!
There is a good thread on here about 315cmh , check it out, there may be folks who can answer the spectrum questions for you.
 
A

Agronut

Well-Known Member
coreywebster said:
To get a high yield you need the lighting, you have that bit, but you need veg time, and plant count and to fill your space. Scrog is a great way to get good numbers but trying to fill that 5x5 with one plant rather than 5 or 7 will impact your bud size and weight.
Strain is also a big factor.
Just remember you can have all the light in the world but without the rest of the variables been right you wont hit those high GPW or GPSF figures.


Also
@Agronut having the different spectrum will change the structure of the plant, internode space and bud size will vary depending on which combo you use, you may as well try two flowering bulbs and then next run try mixing the veg and flower spectrum. I would also consider doing the same in veg with the veg bubs and combo of both bulbs.
I have only flowered once with cmh but I used that 3100k bulb for veg for many grows and its an amazing veg light to be honest. The spectrum is great all round.

Regarding the temps, you should be exchanging air regardless assuming you were not adding co2. Its not just about removing the heat, its about maintaining co2 to a reasonable level, without it you are limiting your plant growth and bud production.
Its simple enough though, the heat will be twice the rise from ambient with 2 315s than it was with one, roughly, provided the cheap china light was not air cooled which I gather it wasn't or you would of mentioned it. You want a quality fan to extract.
Sorry I cant add more about the results of the bulb combos, but had to reply due to the apparent lack of air exchange!
There is a good thread on here about 315cmh , check it out, there may be folks who can answer the spectrum questions for you.
Click to expand...
Hey thanks so much for the reply and knowledge-share; I’m new to this board but definitely not to this game, although my experience (for years) has been in the sun up near Big Sur growing monster God Bud and Blackberry Kush trees....indoor 5x5 is definitely a learning curve! I’ve got two 6-inch inlines in/out thru charcoal, respectively, but concerned that extra HVAC might be in order. And I’ll definitely look for the thread you mentioned for spectral opinions. Thanks Corey Webster!
 
coreywebster

coreywebster

Well-Known Member
Agronut said:
Hey thanks so much for the reply and knowledge-share; I’m new to this board but definitely not to this game, although my experience (for years) has been in the sun up near Big Sur growing monster God Bud and Blackberry Kush trees....indoor 5x5 is definitely a learning curve! I’ve got two 6-inch inlines in/out thru charcoal, respectively, but concerned that extra HVAC might be in order. And I’ll definitely look for the thread you mentioned for spectral opinions. Thanks Corey Webster!
Click to expand...
No worries man! Glad to be wrong in this case. We see it too often where folks think they can get away without ventilation.
I hope to see some experiments with your bulb/spectrum mixing in the future!

Welcome to RIU Agronut. :bigjoint:
 
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