630w DE - CMH?

since1991

Well-Known Member
Dude..enough with the bowshit. You dont know what your talking about in regards to light amd carbon dioxide. You can copy amd paste and link all you want. Ive got many many years on you kids. The light for the area in question is just fine without co2. Your a third grow pro. This site has many of your kind.
 

Dynamo626

Well-Known Member
Dude..enough with the bowshit. You dont know what your talking about in regards to light amd carbon dioxide. You can copy amd paste and link all you want. Ive got many many years on you kids. The light for the area in question is just fine without co2. Your a third grow pro. This site has many of your kind.
ok lol no idea what im talking abought. Alpinstash the vid that was posted ware the commercial facility is running 5 315s over a 4x8s said they are open to questions. ask how much co2 they are pumping in and why.
 

Yodaweed

Well-Known Member
ok lol no idea what im talking abought. Alpinstash the vid that was posted ware the commercial facility is running 5 315s over a 4x8s said they are open to questions. ask how much co2 they are pumping in and why.
5 cmh over a 4x8 is gonna have a ton of spots without light. a single 315 cmh covers a core flowering area of about a 2x2 or 3x3 max
 

DesertHydro

Well-Known Member
i dont think he is saying it wont help or contribute to yield, density etc its just that the law of diminished returns comes into play at that point. lets not get too out of control here haha.

obviously if you add more light and can control the temps you are going to see some added benefit, whether it from less shadowing, more intensity, uniformity etc but there is a cut off point at where the input/outputs are going askew.

that being said, its 315w which as far as most growers are concerned is pretty minimal. i personally prefer to be efficient as possible without limiting my plants if possible.
 

Dynamo626

Well-Known Member
CMH is not more efficient than HPS. Both get around 1.9umol/s/w. If anything cmh less efficient since a good double ended HPS bulbs can produce 2.1umol/s/W.
ya did your math wrong 600 hps se puts out an average of 1140 thats the same as a 315 cmh so yes they put out the same amount of light but you didnt acount that the cmh does it on 315w not 600
1140 divided by 600 is 1.9
1140 divided by 315 is 3.6
honestly the ppfd chart i looked at for 315 put it at 1100 umole/sec the math sais that is 3.49/watt
 

nizzaofficial

Active Member
CMH is not more efficient than HPS. Both get around 1.9umol/s/w. If anything cmh less efficient since a good double ended HPS bulbs can produce 2.1umol/s/W.
CMH is more efficient than HPS for its plant useable light, The photons in HPS are big where as in CMH they are small,

CMH Has a better spectrum good amounts of UV for better quality, Run cooler, HPS gives off a lot of heat. CMH CRI 92, DE HPS CRI 32,

That being said both CMH and DE HPS are both great in there own way, Some people like to mix them both together,
 

wietefras

Well-Known Member
ya did your math wrong 600 hps se puts out an average of 1140 thats the same as a 315 cmh so yes they put out the same amount of light but you didnt acount that the cmh does it on 315w not 600
1140 divided by 600 is 1.9
1140 divided by 315 is 3.6
honestly the ppfd chart i looked at for 315 put it at 1100 umole/sec the math sais that is 3.49/watt
No I did not. They are lying to you about the CMH. Look up a datasheet for a CMH bulb. Its really around 1.9
 

Dynamo626

Well-Known Member
that is referring to the light wave in nanometers. blue has a much smaller wave i think between 400 and 500 nm
and red a longer wave between 600 and 700 nm. blue photons actually carry more energy than red.
just an after thought. funny how light can be both a wave and a particle. love quantum physics lol.
No I did not. They are lying to you about the CMH. Look up a datasheet for a CMH bulb. Its really around 1.9
soon all lighting lies will be revealed to me. it can be frustrating comparing charts that have been posted by manufactures, especially since reflector size and shape affect readings. that and lowering or raising a light by just a few inches greatly changes the ppdf readings. early January my shop is building me a light testing lab.
like the one at Monstergardens. just ordered the par meters.
 

OneHitDone

Well-Known Member
there is a point that photosynthesis stopes being limited by the amount of light and instead restricted by the amount of co2 available remember photosynthesis requires both. in a 4x8 at about 1600w of hps all the abought 400ppm of co2 in the air is being used any more light added can not be used by the plant unless co2 is supplemented. if you are using cmh lighting its about 447w per 4x4 or about 900w per 4x8

with this in mind three 315s is perfect for the area all the available co2 is being utilized with little wasted light. if you add co2 to the area it is wasted because there arnt enough photons to process it. if you add more another 315 there isnt enough co2. if you are going to use more than 3 315s you must add co2 to use the extra light
1 630 cant cover the area, 2 630 is overkill if you cant seal the area and add co2.
Question for you Brother @Dynamo626 since you seem to really know your way around CMH. Have you ever heard of anyone trying to burn (3) 315's on a single 1000W Ballast the way some have burned (2) 600W HPS?
 

OneHitDone

Well-Known Member
I am quite impressed with the conversation in this thread - even with all the skewed info and difference of opinion everyone is managing to keep their shit together :clap:
Clearly cmh being bulbs is drawing a much more level headed group of participants than the diode threads :P
 

since1991

Well-Known Member
I am quite impressed with the conversation in this thread - even with all the skewed info and difference of opinion everyone is managing to keep their shit together :clap:
Clearly cmh being bulbs is drawing a much more level headed group of participants than the diode threads :P
Never ventured much into the led threads.Pretty rough huh?
 

since1991

Well-Known Member
That HLG 550 sounds like the bees knees. If one could get 2 pounds...or hell...even a pound and a half from one of those in a 4x4..holy sheeitt !!! That changes up the whole frikin book.
 

Dynamo626

Well-Known Member
Question for you Brother @Dynamo626 since you seem to really know your way around CMH. Have you ever heard of anyone trying to burn (3) 315's on a single 1000W Ballast the way some have burned (2) 600W HPS?
Havent heard of that however even if the wireing was possable the cmh lighting runs on low frequency square wave ballasts. Hps run on a high frequency ballast
 
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