cfl selection advise please

Hey all. Just messing around with me PC grow box, currently have a 70w 3000k metal halide in it but with our summer temps up around 85 to 95 its hard to keep temps reasonable. So I was considering switching to cfls. locally I have found only a couple of reasonable wattage cfls. One being a Nelson branded 48w availiable in 3000k or 5000k at $16 ea (no info on lumens for these)and the others are a Philips brand 24w in a 2700k or 6500k at around 1500lm for $6 each. Has anyone used either of these and which would you recommend for my PC grow box? I also want to setup another PC box for a couple of clones. Which would be best performance and cost wise for both boxes? I was thinking the Philips cfls as they seem to be cheaper per watt than the Nelson and also better colour temps for growing. Thanks guys

you can get two 105watt cfl's on amazon right now for $25 and free super shipping. buy them, use one, save the other. make a hood out of home depot stuff. you'll be swimming in green.

Is the ballast for the light in the box? and if so can you move it to the outside? or maybe turn up the fans....park the spare glowing computer next to the A/C....

Oh and the 42w cfls are decent you can get them at the harware store or wally world.

Cheers,
SilverSerf

I have the ballast on the outside mounted on the back of the box and theres a squirrel cage fan each for intake and exhaust. They both run full speed 24hrs unfortunately I don't have any air-conditioning so that's not an option. But I do have a few more squirrel cage fans I can add once I take out the mh ballast.
So if I was to use 4 of the 24w or 2 of the 48w, that would be sufficient?
Would it be best to have say half 2700k and half 6500k? Or just have all 6500 for veg and swap to 2700k for flower?

Are you talking about these:

http://www.amazon.com/gp/product/B0058KJNYQ/ref=as_li_ss_tl?ie=UTF8&tag=rollitsig-20&linkCode=as2&camp=1789&creative=390957&creativeASIN=B0058KJNYQ

Too bad you can't mix up the K ratings on them, and it's .50 cents short of free shipping. I couldn't find a lumen output but it's probably right around 6900.

Another quick question, what reflective surface will be better for the inside of the box? I see a lot of PC growers using the silver reflective stuff, would that be better than painted white like my box is now?
Thanks

catch, those are the ones i just got. i don't think you can mix to 2700k. mine came in as 6500. which is just fine, for now. and you can't beat that deal with a stick.

baskarz said:

Another quick question, what reflective surface will be better for the inside of the box? I see a lot of PC growers using the silver reflective stuff, would that be better than painted white like my box is now?
Thanks

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the reflective surface is either Mylar(which is 95%reflective)or its foil(58% reflective but horrible to use it creates hotspots and will burn plants,FOIL=no no)and white is like 70%reflective i would say use mylar

Rcb said:

the reflective surface is either Mylar(which is 95%reflective)or its foil(58% reflective but horrible to use it creates hotspots and will burn plants,FOIL=no no)and white is like 70%reflective i would say use mylar

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I wouldn't be so quick to pass along the hot spot theory. I haven't seen a shred of evidence to support this, only hearsay and I would doubt it's likely to occur with a 400w HPS let alone some wimpy CFLS! Also Mylar can be just as crinkly as foil and more reflective so what does that tell you.

Ok so here are the same bulbs as the 105w just in 45w, you get 4 for $18.50 free shipping (6500K only). These bulbs are kinda big so you should be able to fit 2 in your PC, and the other two you could use for your other box you talked about.
http://www.ebay.com/itm/Julius-Studio-Photography-Lighting-Bulbs-Day-Light-Bulb-PB45-4P-New-PB45-/190584888749?pt=LH_DefaultDomain_0&hash=item2c5fbe9dad

What I've learned about the foil & hot spot theory is it is not necessarily true. In my first grow I used aluminum tape inside the entire box and I didn't have a problem with hot spots, inside temps where always around 80°F-90°F. I could see how you could get hot spots though, not enough ventilation in the box, no fan blowing on the bulbs, etc. In the long run I would rather use Mylar or an emergency blanket. Emergency blankets are somewhat translucent though.