Is 315W CHM ok for a 3x3 tent?

J

JHake

Well-Known Member
Hello RIU.

I own a 3x3 tent. I have a 400W HPS on it.

I've read varying things about lightning, watts per square feet, etc.

Wanted to know your opinions about going with 315W CHM...would it be an upgrade from the HPS 400W?
 
DankWilliamsSr

DankWilliamsSr

Well-Known Member
I run a 315 over a 4x4 area and pulled 1.3 grams per watt. But I know more is possible. I think you would be happy with it. Not sure about compared to a 400w hps though because I haven't grown with them.
 
J

JHake

Well-Known Member
That's a great yield.
I'm not sure about the hoods that i've seen these CMH come with. Im from South America and there aren't as many companies and products like USA and Europe.
Which hood do you use? At least i could check the specs.

Thanks for your answer.
 
Horselover fat

Horselover fat

Well-Known Member
400w hps is a little more powerful than a cmh. ~530 umol/s vs 700 umol/s. Doesn't necessarily mean you'll yield less, but the hps should have a higher max yield. White light is much nicer to work under so that's a plus for the cmh. I'd say the bluer spectrum is better too and plants should grow a little more compact.
 
Opie1971

Opie1971

Well-Known Member
I use a Sunburst 315cmh in a 4x4 in the winter (for more heat), and it’s really not enough to completely ‘fill’ the whole 16sq ft. I think you’d be great for a 3x3.
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J

JHake

Well-Known Member
Thanks everyone for the answer.
The vertical hood seems to be the standard option for growers.

I forgot to clarify a, maybe, important detail: the lamps i'm talking about are 2x150W each, General Electric Constantcolor CMH 150W CMH150/TT/UVC/730/340.
 
Horselover fat

Horselover fat

Well-Known Member
JHake said:
Thanks everyone for the answer.
The vertical hood seems to be the standard option for growers.

I forgot to clarify a, maybe, important detail: the lamps i'm talking about are 2x150W each, General Electric Constantcolor CMH 150W CMH150/TT/UVC/730/340.
Click to expand...
Not all cmh bulbs can be used in both horizontal and vertical orientations. That bulb also should not be used in an open fixture!

You'd really want three or four of them too.
 
DankWilliamsSr

DankWilliamsSr

Well-Known Member
JHake said:
That's a great yield.
I'm not sure about the hoods that i've seen these CMH come with. Im from South America and there aren't as many companies and products like USA and Europe.
Which hood do you use? At least i could check the specs.

Thanks for your answer.
Click to expand...
I'm using DLI (Dutch lighting innovation's) they are an open sided hood. Same style as the gavita 150w hoods
 
farmingfisherman

farmingfisherman

Well-Known Member
I used a Sun System Boss 315 cmh with a 3100k bulb in a 4 x 4 along with two china made led panels. Total actual watts was 515.. I was happy with the results considering it was my first indoor grow. I'd think a 315 in a 3 x 3 would be great, would you use it only for flower? I ask cause I don't recall many threads using the 4000k bulbs which I presume are for veg..
 
NukaKola

NukaKola

Well-Known Member
JHake said:
Thanks everyone for the answer.
The vertical hood seems to be the standard option for growers.

I forgot to clarify a, maybe, important detail: the lamps i'm talking about are 2x150W each, General Electric Constantcolor CMH 150W CMH150/TT/UVC/730/340.
Click to expand...
315w CMH will give tighter internode spacing and less stretch than 400w HPS, more resin production, possibly slightly less or comparable yield.

I would go with a 315w bulb over 2x 150w. It will give much better penetration and honestly I think you would be disappointed going to 2x 150w from a 400w HPS. Anything under the top 10-12” will be larf.
 
NukaKola

NukaKola

Well-Known Member
Personally I don’t think a 315w is a huge upgrade over a 400w HPS, more of a sidegrade since they both have their pros and cons.

Have you considered going LED?
 
J

JHake

Well-Known Member
NukaKola said:
315w CMH will give tighter internode spacing and less stretch than 400w HPS, more resin production, possibly slightly less or comparable yield.
Click to expand...
Thanks man.
The other option is a 400W CMH bulb, also from General Electric, i believe the same Constantcolor line from GE.

About the LED:
Yes, i did think about it, but here in my country it seems like we are always a few months/years behind, and i don't want to spend a good amount of money and be outdated a few months from now.
But sooner or later i will go with some LEDs fixtures, until then i guess i'll stay with the HPS and don't go with the CMH.
I will ask a good LED producer here about their products...would you mind if i post the info here and you tell me what you think about their lights?
 
NukaKola

NukaKola

Well-Known Member
JHake said:
Thanks man.
The other option is a 400W CMH bulb, also from General Electric, i believe the same Constantcolor line from GE.

About the LED:
Yes, i did think about it, but here in my country it seems like we are always a few months/years behind, and i don't want to spend a good amount of money and be outdated a few months from now.
But sooner or later i will go with some LEDs fixtures, until then i guess i'll stay with the HPS and don't go with the CMH.
I will ask a good LED producer here about their products...would you mind if i post the info here and you tell me what you think about their lights?
Click to expand...
If you did go with CMH I would recommend Phillips or Hortilux.

Feel free to post the LED specs. Where you are located, is importing not an option?
 
J

JHake

Well-Known Member
NukaKola said:
Feel free to post the LED specs. Where you are located, is importing not an option?
Click to expand...
I'm from Argentina. Importing is expensive on taxes mostly. To ship a finished product i guess would be very expensive, but maybe i could import the chips and driver and mount it by myself, i have certain knowledge and experience on electronics. What LED do you recommend? I could search and check the specs at least.

Horselover fat said:
If you are not looking for power savings then a 600 hps is very good for a 3x3.
Click to expand...
Funny thing here is that i can buy almost 3 kits of 400W HPS and ballast for the same price i can buy a 600W HPS and ballast kit, not sure why lol.
 
NukaKola

NukaKola

Well-Known Member
JHake said:
I'm from Argentina. Importing is expensive on taxes mostly. To ship a finished product i guess would be very expensive, but maybe i could import the chips and driver and mount it by myself, i have certain knowledge and experience on electronics. What LED do you recommend? I could search and check the specs at least.



Funny thing here is that i can buy almost 3 kits of 400W HPS and ballast for the same price i can buy a 600W HPS and ballast kit, not sure why lol.
Click to expand...
You can order a Kingbrite or Meijiu board or strip fixture from Alibaba. The low cost should offset the high shipping cost. They use Samsung diodes and mean well drivers.

The strips do cost a bit more and shipping is higher due to the size so boards might be a better option in terms of cost.

2 240w boards Dimmed would give good coverage.
 
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