How many "CFL" watts per Sq Ft is necessary for a good CFL grow?

C

carno

Well-Known Member
Hello all. Here is my setup

2 x 3 x 4.5 Tent
165cfm Filter
4in scrubber
184 total cfl watts from 8 bulbs
2 48watt t5 bulbs (left them in there after germination and early veg)
Temps are around 78 - 82
2 plants in 3 gal smart pots (some version of girl scout cookies and MK Ultra)

I just flipped them to 12/12. I was waiting until I could get my Hps but they are getting too big. This grow started in august. First grow for me. I understand that I will not get the quality, nug size or yield that I would get using an hps bulb. But I also understand that I can get some descent quality using cfls.

Is 184 watts from cfls and 96 watts from t5s sufficient for a 2 x 3 x 4.5 tent? My one worry about adding more bulbs or watts is temperature control. I probably skimped too much on the fan. 165cfms through a scrubber is barely holding at 80. I can get the outside temps around the tent lower, but that is my last option outside of getting a new fan)

thanks
 
whitebb2727

whitebb2727

Well-Known Member
The t5 will help. You got plenty for two plants. At a minimum shoot for 100 actual watts for veg and 150 for flower. Then 50 to 100 watts for each additional plant.
 
C

carno

Well-Known Member
thanks for the responses. it looks like I am going to have to take some light out. Since I changed to 2700K and switched to 12/12 the temps got up to 88. I had to keep the outside of the tent cold in order to lower the temps. Should I subtract 2 cfls or te 2 t5's?
 
C

carno

Well-Known Member
all my cfl's are paired with a splitter. Im thinking of making a few pairs single to lower the temps.
 
C

carno

Well-Known Member
superbak3d said:
My suggestion, get a single 250 or 300w CFL.

http://www.amazon.com/dp/B00HG1J36I?m=A2WRS4X4C0GMOQ&ref_=v_sp_detail_page

I've been growing CFL for years, and these work the best.

Here's my bud under a single 250w cfl

View attachment 3545398 View attachment 3545399
Click to expand...

The only reason I won't get a that big cfl is because I plan on getting a 250w or 400w HPS. te 300w cfl plus reflector is $75 and up. if I add another to that I can get the HPS. great idea and great looking plants.
 
superbak3d

superbak3d

Well-Known Member
carno said:
The only reason I won't get a that big cfl is because I plan on getting a 250w or 400w HPS. te 300w cfl plus reflector is $75 and up. if I add another to that I can get the HPS. great idea and great looking plants.
Click to expand...
Well the good thing about the cfl and reflector is it's all set for an HPS bulb, all you need is the matching ballast.
 
C

carno

Well-Known Member
superbak3d said:
Well the good thing about the cfl and reflector is it's all set for an HPS bulb, all you need is the matching ballast.
Click to expand...
Great point. I will consider that. I think I am definitely going to get a new exhaust fan. 165cfm isnt enough. Can't even control CFL temps. Thanks
 
C

carno

Well-Known Member
SPLFreak808 said:
50 watts in a foot would be okay. If your in a crowded area, bottom growth WILL get left in the dark.
Click to expand...
I put up a scrog. I have done some lollipopping along the way. Almost time to do it again. I just don't want to do to much to it at once. Right now it is switching over so I am going to leave it alone for a few days. The canopy is pretty descent. It will probably be another week before I can tell what will and won't reach the canopy. thanks
 
Mount

Mount

Well-Known Member
Sometimes its deceiving talking watts, lumens per square foot is the best way to determine how much light you need.


  1. In a nutshell…

    Lumens per square foot:

    Minimum amount of lighting needed is around 2000 lumens per square foot.
    (Two – 23 watt CFL’s, per square foot*)

    Mid range is around 5000 lumens per square foot.
    (Three – 23 watt CFL’s, per square foot*)

    Optimal is 7000-7500, or higher, lumens per square foot.
    (Five – 23 watt CFL’s, per square foot*)

    *I’m only using CFLs as a reference here, with the assumption they’re kept at a distance of 3 – 5 inches from the plant. It is important to understand that the “penetration” (the farthest measure that quality light reaches down into the plant canopy) will at best be only a few inches deep.
The above was copied from here:
http://www.growmedical420.com/how-many-lumens-or-watts-per-square-foot-of-light-do-i-need/
Post a few pictures when you have time. Happy Growing
 
You must log in or register to reply here.
Top