CFL Coverage Area Question

[downtoearth]

Quick question. How many plants can be supported from grow to harvest with 13, 2700k 26w CFL's and 13, 6500k 26w CFL's The picture below shows the setup. Each bulb is staggered. This is supposedly equivalent to 2,600 Watts Incandescent lighting.

 

[ak-51]

So that's 676 total watts of CFLs right? Plant count is kind of irrelevant. You could have 1 plant large enough to be lit by the entire rig (nice rig by the way), or you could SOG a bunch of plants under it.

I would guess that the effective area would be no more than 1 square foot per light, not cumulative, meaning that about 6 inches out from the direct footprint of your rig is as far as you would want to go.

Just by looking at that I think you could do a nice SOG-like run with 8 plants. Maybe vegging for 10-14 days? You'd just have to set them into flower at the right time to make sure they don't get too big. You just can't have a huge canopy or you'll be making too much popcorn at the bottom.

For a member more experienced than myself to help you they might want more exact dimensions of your rig.

I have a couple questions about your setup too:
-Is that where you're running, right next to the window? Are you running autoflowers?
-That's a lot of heat your going to be generating. Have you considered switching to HPS or LED? I run CFLs for little stuff that I jam in corners, but my feeling is that once you get big it becomes too inefficient and it loses much of it's advantage over HPS. I have seen some really great CFL grows on here though.

 

[downtoearth]

@ ak-51, yes 676 total watts of CFLs. I'll do my homework for SOG grows for sure. I am running that setup next to those windows. It's actually in a sun room lol I carry the plants outside in the sunshine except when it's really bad weather. Those are auto-flowering plants. I don't really have the cash for anything else right now so I'm using these lights to keep these plants on 24 hours of light to get some more growth on them. They started to flower when they were really short where there wasn't much growth. Hoping to stretch them out a bit. Any suggestions with this idea?

 

[supersmallgiant]

That would flower a 3' x 3' foot print.

 

[GreenMachine22]

If you can replace thoes with 42 watters and u should be able to get a nice yield out of two plants..

 

[downtoearth]

Thanks supersmallgiant and GreenMachine22. That helps me put things into perspective so I can think of a realistic grow. Not sure if a 42 watter will fit the same as the others do. I'll look into it for sure.

 

[h.h.]

18 hours should work as well and save ya a couple bucks...6500k for veg 2500k doesn't do much good and adds heat. 6500k you can bury the tops in the light with no burn.
I figure 2 or 3 lights per plant up to about 18", starting to lose efficiency at around 12" outside as much as practical except young plants in hot or cold weather

 

[downtoearth]

Thanks man. I'll do the 18 instead of 24. The heat thing isn't really a big issue at the moment. I have a nice fan blowing just above the plants, aimed just below the bulbs in my sun room. I carry them outside every day. Pain in the ass for sure lol.

18 hours should work as well and save ya a couple bucks...6500k for veg 2500k doesn't do much good and adds heat. 6500k you can bury the tops in the light with no burn.
I figure 2 or 3 lights per plant up to about 18", starting to lose efficiency at around 12" outside as much as practical except young plants in hot or cold weather

 

[IwannatokeNbone]

your coverage id say would be about what mmmmm 5-6 inches. with that much power n heat im sorry to say but id rather have a 150hps, 26 watt cfls dont do much im afraid. keep in mind also that with cfls bulbs set up via the coil design your only getting about half the lumesn u pay for in watts, something u cfl guys tend to forget, so your grow is roughly 350 watts of 26 cfls that u pay the rate of 700 watts for, remeber coiled bulb, inverse square of light, etc, your paying for heat, n for light to boucne of other lights and themselves. a cfl grow over a few hundred watts is foolish, just keeping it real. id grab a 150-250hps, youll yeild more and have less heat and a cheaper electric bill.

 

[downtoearth]

I understand. I'm just glad that I am out in the country and can take these girls outside to enjoy the benefits of sunshine! This setup was done about 2.5 years ago, when I had a hydro setup. They were supplemental lights to be used for some clones and or seedlings. Now I'm just using them to fill in some dark hours at night before bed. I didn't know much about the auto flowering plants and in retrospect, shouldn't have bought them. I would have rather grown regular plants because I do have the time and space for them. Oh well.

I looked in a local store. I can get a M.H. 400W HPS bulb for 21.98 Should I get two and just let these CFL's go?

your coverage id say would be about what mmmmm 5-6 inches. with that much power n heat im sorry to say but id rather have a 150hps, 26 watt cfls dont do much im afraid. keep in mind also that with cfls bulbs set up via the coil design your only getting about half the lumesn u pay for in watts, something u cfl guys tend to forget, so your grow is roughly 350 watts of 26 cfls that u pay the rate of 700 watts for, remeber coiled bulb, inverse square of light, etc, your paying for heat, n for light to boucne of other lights and themselves. a cfl grow over a few hundred watts is foolish, just keeping it real.

 

[IwannatokeNbone]

i would, i guess if there two years old u already got your moneys worth out of them.

 

[blank85]

Try 2 to 4 plants. I veg with CFL's they are great.

 

[GreenMachine22]

I understand. I'm just glad that I am out in the country and can take these girls outside to enjoy the benefits of sunshine! This setup was done about 2.5 years ago, when I had a hydro setup. They were supplemental lights to be used for some clones and or seedlings. Now I'm just using them to fill in some dark hours at night before bed. I didn't know much about the auto flowering plants and in retrospect, shouldn't have bought them. I would have rather grown regular plants because I do have the time and space for them. Oh well.

I looked in a local store. I can get a M.H. 400W HPS bulb for 21.98 Should I get two and just let these CFL's go?

Keep the CFLs for veg and get an hps conversion bulb if u have a mh ballast

 

[downtoearth]

Keep the CFLs for veg and get an hps conversion bulb if u have a mh ballast

Thanks for the idea man!

 

[ak-51]

I'll agree that running CFLs on a large scale is wasteful. Maybe some people don't have access to a hydro shop and can't order stuff though. If you can get purpose built grow gear then I would move to that. Upgrading to 42w CFLs would be costly. I think the GE 42s I buy locally are 8 or 9 dollars a piece. Over the last 2 years I've probably spent over $120 on CFLs. If you're primarily using the sun though I'm not sure how critical it actually is. If you want to move indoors I would upgrade to HPS/MH or LED (if you're brave/foolhardy enough). I've never run autoflowers either. I don't see any benefit to them if you're running indoors besides maybe hitting them with more light during flowering.