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Ceramic Metal Halide (CMH)

RikkiTikkiTavi

RikkiTikkiTavi

Member
how many and what 315w CMH layout would you guys recommend for a 15' by 21' room lined with orca film?

i was all set to go with gavita 1000 DE's, but the more i read about the CMH, the more it looks like the way to go.
 
R

redclover

Member
RikkiTikkiTavi said:
how many and what 315w CMH layout would you guys recommend for a 15' by 21' room lined with orca film?

i was all set to go with gavita 1000 DE's, but the more i read about the CMH, the more it looks like the way to go.
Click to expand...

Those Gavitas are special. I'd personally go with the 860w CDM with OG or Luxor hoods due to being CMH partial. Gavitas do have more PAR, intensity, and replaceable reflectors so...
 
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RikkiTikkiTavi

RikkiTikkiTavi

Member
i'm moving into a warehouse in the next couple months, so the dimensions aren't set.

node while that's a beautiful set up, i'm limited to 36 plants in flower and height restrictions on vegging plants before plant count comes into play, under current legislation in my state. after the first cycle i'll be building a second flower room and a veg (some would call it pre-veg) room so the same day i harvest in one room, i can flip the next room into flower, clean and prep the room i harvested from, clone, veg/pre-veg, move them into that room, rinse and repeat. i was looking at spacing of 3'x3' for each plant, 5 rows of 7 to accommodate the gavita's more rectangular light pattern. the specific dimensions of the room aren't set in stone as i'll be building it out from scratch.

i'm running vert right now. this is my first go at it and while there are aspects i like, i'm not completely sold that i want to build my new space around it or that it will yield better then bigger plants in a more traditional set up since i'm capped at 36 plants, but i'll chew on it some more.

i'm not married to the 315w, i do like the idea of a more diffuse light source, set at a static height right through to harvest so i don't have to raise the lights through each grow. over time i'm looking to get things dialed in and automated as much as possible, so i can do the drive when i want to check in and spend some time with the ladies rather than have to, and be able to go away for the weekend without having panic attacks.

maybe a gavita DE and CMH mix? i was looking at 9-12 gavita's, so maybe half and half in a checkerboard pattern? that would lower my electric bill and give me a nicer spectrum.
 
R

redclover

Member
RikkiTikkiTavi said:
i'm moving into a warehouse in the next couple months, so the dimensions aren't set.

node while that's a beautiful set up, i'm limited to 36 plants in flower and height restrictions on vegging plants before plant count comes into play, under current legislation in my state. after the first cycle i'll be building a second flower room and a veg (some would call it pre-veg) room so the same day i harvest in one room, i can flip the next room into flower, clean and prep the room i harvested from, clone, veg/pre-veg, move them into that room, rinse and repeat. i was looking at spacing of 3'x3' for each plant, 5 rows of 7 to accommodate the gavita's more rectangular light pattern. the specific dimensions of the room aren't set in stone as i'll be building it out from scratch.

i'm running vert right now. this is my first go at it and while there are aspects i like, i'm not completely sold that i want to build my new space around it or that it will yield better then bigger plants in a more traditional set up since i'm capped at 36 plants, but i'll chew on it some more.

i'm not married to the 315w, i do like the idea of a more diffuse light source, set at a static height right through to harvest so i don't have to raise the lights through each grow. over time i'm looking to get things dialed in and automated as much as possible, so i can do the drive when i want to check in and spend some time with the ladies rather than have to, and be able to go away for the weekend without having panic attacks.

maybe a gavita DE and CMH mix? i was looking at 9-12 gavita's, so maybe half and half in a checkerboard pattern? that would lower my electric bill and give me a nicer spectrum.
Click to expand...

That would be the best of both worlds. I'd hang the 942s (more blue) with the Gavitas above. I'm sure you can get very close to plants with vert 315s.
 
e_24

e_24

Active member
It's also great to know that I can use a 330w allstart in my 2x3 tent, and have 55w psf. The only problem is getting a reflector to spread my light properly.
 
N

nodestar

Member
RikkiTikkiTavi said:
i'm moving into a warehouse in the next couple months, so the dimensions aren't set.

node while that's a beautiful set up, i'm limited to 36 plants in flower and height restrictions on vegging plants before plant count comes into play, under current legislation in my state. after the first cycle i'll be building a second flower room and a veg (some would call it pre-veg) room so the same day i harvest in one room, i can flip the next room into flower, clean and prep the room i harvested from, clone, veg/pre-veg, move them into that room, rinse and repeat. i was looking at spacing of 3'x3' for each plant, 5 rows of 7 to accommodate the gavita's more rectangular light pattern. the specific dimensions of the room aren't set in stone as i'll be building it out from scratch.

i'm running vert right now. this is my first go at it and while there are aspects i like, i'm not completely sold that i want to build my new space around it or that it will yield better then bigger plants in a more traditional set up since i'm capped at 36 plants, but i'll chew on it some more.

i'm not married to the 315w, i do like the idea of a more diffuse light source, set at a static height right through to harvest so i don't have to raise the lights through each grow. over time i'm looking to get things dialed in and automated as much as possible, so i can do the drive when i want to check in and spend some time with the ladies rather than have to, and be able to go away for the weekend without having panic attacks.

maybe a gavita DE and CMH mix? i was looking at 9-12 gavita's, so maybe half and half in a checkerboard pattern? that would lower my electric bill and give me a nicer spectrum.
Click to expand...


You'll always be in your own individual situation with distinct challenges and that's part of the fun. Your plant limit is a restriction that will shape your own unique grow.

Keep in mind that Vertical growing has more advantages than just being the Highest Yield per Square foot/Meter. (an advantage that doesn't apply to people with plant number limitations) It's also simple. Can be cheaper. Takes advantage of Vertical space leaving you more Horizontal space. Etc etc.

The 315's highlight some of the inherent advantages of Vertical Growing. Often reflectors can be as expensive as the bulb ballast combo. So you're paying double for less efficient light and heat distribution. The 315's don't generate the kind of heat a 1000 watt HPS would. So in an open warehouse you don't need cooling tubes or other complicated/expensive apparatus. Keeping it simple and clean.

In my opinion there are some misconceptions about plant size when dealing with plant limitations. Growing tree's will not always be the most efficient use of your plant count. Not to mention the extra labor and attention tree's start to demand. They can be unwieldy and require more maintenance depending on your grow method.

Since space isn't a restriction your main commodity is time. You'll find a happy medium between a 1 gallon single cola and a 30 gallon monster. But I my opinion the 1 gallon side of the fence will always favor indoor growing.

Take it all with a grain of salt. You'll find your perfect setup somewhere between whats "technically best" for your room with whats "practically best" for you.
 
M

mr.good

Member
Cmh is awesome, the resin production that it produces is way better then the resin production from my 600 watt HPS. However the weight is less with the cmh then HPS (which I expected) but the resin production the cmh produces is crazy awesome. Also I noticed during flower with this light it seems to flower quicker.
 
tenthirty

tenthirty

Member
The numbers in the study are comparable to what I have been experiencing for the last 6 or 8 months.
These thing are superior to HPS in all ways.....except initial cost.
 
N

nr nodes

Member
Sorry but watching these cmh grows I have yet to see the equivalent yields being claimed. Spectral quality and earlier finish times make sense, but over a month less daylight for 30% more weight? Show me please.
 
N

nr nodes

Member
So their HPS control yielded a mere 1.375 lbs/1k, yet they were able to produce 2.59 lbs/1k with their own product, under otherwise identical conditions? What, did they have the HPS room dimmed 50% or something?
 
D

Drek

IMO, yield has less to do with light, and more to do with gardening technique and experience.
Exactly why a 600 watt HPS can outdo a 1k.

Let's see a Heath Robinson grow with multiple 315's or 400 CMH. The results might be surprising.
 
R

redclover

Member
Jhhnn said:
Anybody using the 860 CMH? Anybody familiar with this reflector?

http://www.ebay.com/itm/8-Vertical-...9277891?pt=US_Hydroponics&hash=item20d00a1fc3

Circumstances dictate the use of a vent hood, plus I already have 2 suitable ballasts.

Opinions & experience, please!
Click to expand...

I have two of these bulbs. I used them bare vert on a couple 12/12 from seed pheno runs. Frostiest plants I've grown were with this bulb, but I wasted half the light from short plants...so switched to LED. They're as hot as a 600w HPS, highest CRI of any bulb, BLINDING, and ridic PAR. I'm not a fan of reflectors blocking UV. When fall hits I'll try this bulb bare vert again with big veggers.

Bigshrimp looked to be doing great with bare vert.
 
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