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630 watt cmh dual bulb single fixture, what tent does this work best in?

C

CannaN00b

New member
I've read that this open non cooled fixture works best in everything from 4x4 to 3x6. Considering the typical criteria (coverage and penetration) but also more importantly cooling... What would the best tent be for a light like this be?

Some seem to successfully grow 2x315ws in a 4x4x7 tent but that seems like it would be hot.
 
P

Patmando22

Member
4×4×7 would be good you just would have to tweak the cooling a bit to keep it in the perfect zone but definitely doable!
 
zachrockbadenof

zachrockbadenof

Well-known member
Veteran
ii'm using 2x315's in a 4x3.5' tent - works well in cool weather ... nov-march- after march we need some extra cooling - on a side note, not 100% happy with the out-turn weight- i don;t think its enough light- next time aroiund , i'm going to add some add. led lights.. or poss try a 1000w hps
 
C

CannaN00b

New member
zachrockbadenof said:
ii'm using 2x315's in a 4x3.5' tent - works well in cool weather ... nov-march- after march we need some extra cooling - on a side note, not 100% happy with the out-turn weight- i don;t think its enough light- next time aroiund , i'm going to add some add. led lights.. or poss try a 1000w hps
Click to expand...

March till September, is it hard to maintain low enough temps with that set up? It'd be in a air conditioned basement. Would you need to supplement with additional ac on top of that? I'd be running 4 plants only
 
M

Mengsk

Active member
As long as the exhaust fan/duct is near or above the lamp you should be able to get the temperature down. Once the plants fill a screen (horizontal canopy) there's no point to veg further due to stretching.
 
G

gh0stm0de

Active member
Most 315 growers report effective area of coverage between 2x2-3x3. 4' is too wide for effective 315 coverage imo. I use 2.5x2.5 single 315 for moms.

One of the primary dimensions that you should be considering is height. Keeping the room that the tent is placed in will help mitigate the heat a great deal, but is not absolutely necessary.

I would suggest leaving 2' of height between finished canopy and lamp. You will risk losing terpenes if your lamp gets too close.

So consider displacement from the reflector, grow container, and 2' clearance from canopy. What you are left with is the height your plants will be able to achieve comfortably.

You may benefit from a taller tent depending on growth style, and many tent distributors offer 1-2ft height extensions.


Happy growing.
 
DrDee

DrDee

Member
CannaN00b said:
I've read that this open non cooled fixture works best in everything from 4x4 to 3x6. Considering the typical criteria (coverage and penetration) but also more importantly cooling... What would the best tent be for a light like this be?

Some seem to successfully grow 2x315ws in a 4x4x7 tent but that seems like it would be hot.
Click to expand...

CN,
I feel you will do great in a 4x4 with 630 cmh. I'd even go so far as to suggest that you could shut one bulb off during veg. You aren't talking DE bulbs now...are you?
JD
 
zachrockbadenof

zachrockbadenof

Well-known member
Veteran
DrDee said:
CN,
I feel you will do great in a 4x4 with 630 cmh. I'd even go so far as to suggest that you could shut one bulb off during veg. You aren't talking DE bulbs now...are you?
JD
Click to expand...

i'm using 2x315 in a 4x3.5ft tent, and imo the light is insuff- next go around i'm addin led's to supplement the cmh's - maybe 2 , maybe 4 cheap ufo's or something similar … I have a 1000w mh/hps, but it mite pose a heating issue... decisions...decisions...
 
DrDee

DrDee

Member
zachrockbadenof said:
i'm using 2x315 in a 4x3.5ft tent, and imo the light is insuff- next go around i'm addin led's to supplement the cmh's - maybe 2 , maybe 4 cheap ufo's or something similar … I have a 1000w mh/hps, but it mite pose a heating issue... decisions...decisions...
Click to expand...

Zack,
I know guys vegging with a single 315 in 4x4 tent and flowering with 2 of them. You're talking 50 watts/sq foot now...and you want to add to it. I know nothing of your grow...but could something else be holding back your grows?
JD
 
DrDee

DrDee

Member
Zack,
Had another idea. Read about the Emerson effect. Has to do with light specta and plant growth. Maybe you need to add some red light in there...the 315s are producing the blue but you may be weak at the other end.
JD
 
zachrockbadenof

zachrockbadenof

Well-known member
Veteran
hey drdee…. yeah I heard 50 is optium for growing , i'm at 45, so pretty close... i'm using 3100 bulbs thruout the flowering... BUT... i'm using these hydro crunch bulbs (brand new) that came with the system I bought on line... maybe (probably) not as powerful as the Philips, tho being brand new I figured how much worse the Philips could they be... my choices now are replace the bulbs with Philips, I was thinking do one as a comparison , adding 3 or 4 leds as supplement , or deal with 1000w and the heat they carry along with em…

i miss the good old days when we could just throw some seeds in a vacant lot, give em 1 or 2 hits of ferts over the summer, and have weed for the whole winter... and it was pretty good tooo...
 
DrDee

DrDee

Member
zachrockbadenof said:
i miss the good old days when we could just throw some seeds in a vacant lot, give em 1 or 2 hits of ferts over the summer, and have weed for the whole winter... and it was pretty good tooo...
Click to expand...

Oh man Zack,
I miss that too. Used to be you didn't even have to do any math to grow. Yesterday when I replied I had run your numbers and came up with 52 watts/sq ft. Your getting up there in light intensity to where you may need CO2 to handle all the light. 40 is fine for bloom. I veg at 25 watts/sq ft.

I wouldn't worry about the off brand bulbs. Not to where you should replace them. You have them...so use them.

Seriously on the Emerson effect...it's about the two types of chlorophyl A and B and you probably need to add some small red leds if anything. That's why we used to do the MH/hps mix thing.
JD
 
O

OkieSmokie

Member
i would buy the phillips bulbs now and put those cheapo bulbs in reserve in case a bulb goes out. That way you are running tried and true bulbs and you have a spare. Win/win
 
zachrockbadenof

zachrockbadenof

Well-known member
Veteran
OkieSmokie said:
i would buy the phillips bulbs now and put those cheapo bulbs in reserve in case a bulb goes out. That way you are running tried and true bulbs and you have a spare. Win/win
Click to expand...


yea .. in a 4x3.5ft tent i was going to replace one bulb with a philips to compare.... but i think the space is toooo small for an experiment ... i will order 2 philps n keep the hydro crunch's as reserves...
 
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