CFL's For Seedings?


My feminised AK47 seedings are just about 2 weeks old. Would they like the 2700k cfl’s I have or the 5500k cfl’s they’re under now?


Generally 5500-6500K colored light is used for seedlings or the vegetative growth cycle, and the redder 2700K isn’t used until flowering.

happy growing,



Thanks MacG. I have one other question. If Im trying to determine total wattage and total kelvin for my grow closet, do I just add up those values?
4 100W 2700k CFLs = 400W and 10,800K?


The color number doesn’t add up. It is still 2700K even if you have 4 of them. But, yes, the watts will add up, so roughly with 4 x 100 watt bulbs, you’ll have 400 watts. However, actual watts is what is important, not “equivalent watts”, so if you are trying to determine your bulbs wattage by the description that this bulb is “equivalent to a 100 watt incandescent bulb”, then that is not the true wattage and is irrelevant.

Only the actual watts the bulb uses, which might be in smaller print somewhere on the package, and it should definitely be somewhere on the bulb itself, then that real watt number is what is important.

With CFLs, you want about 40-50 watts per square foot of canopy.



Square ft of canopy? I have a closet 2’x5’x8’ that Im setting up for vegging and flowering after these seedlings grow a bit more. I have the following CFL’s for use in this closet and their actual wattages.
4 23W 2700k cfls and 4 45W 5500k cfl’s. I have these 4 socket assemblies that I am going to hang as in the attached photos. The photos show 2 5500’s and 2 2700’s in one assembly. I had planned to hang to of these assemblies in the closet. Any suggestions?


Your canopy will be about the same as your floor space, assuming you grow your plants to fill the whole area, so your floor space is 2’x5’ and that totals for 10 square feet. 10x40=400 and 10x50=500

This means you need 400-500 actual total watts. There is nothing wrong with using both the 2700Ks and the 5500Ks together.

4x23=92 and 4x45=180 and 180+92=272, a little short, not that you can’t grow a decent plant under these, but it is what it is and it will be hard to get really large dense buds under less than the minimum light.



Bummer. Guess I had better get some more toys! Thanks for the info, kind sir…


you can make Cfl fixtures by using splitters they double bulbs in single outlet. I have a vanity light fixture it has 6 sockets on it standard I fastened a shade to it using 6" duct pipe and put splitters in each socket has 12x23w for a total 273 actual watts I could easily double that again with additional splitters but when you actually do the math a light ballast combo isn’t too much more. I had the vanity fixture and and pipe and made it simply for my clones worked in a pinch I keep it for a back up incase a bulb dies on asunday and my used spare doesn’t work :slight_smile:


Bi mart and dollar store…3 - 3ways with a roasting pan as hood. LOL its working so far…


Here is another example, and with a lot of good design and reflective surfaces, you can get a decent yield, even with home made CFL lighting.



That’s a nice design 400w and some fine bonsi


Beautiful canopy.:grinning:


Holy shit thats sweet…


I used 10 CFL’s on my last grow. 5 2700k’s n 5 6500k’s. And my homemade grow box. With white paint for reflection. I’m also a beginner n right now I’m growing 2 white widows. My last grow was awesome. CFL’s are good. I’m sticking with them. This grow I’m gonna do some mainlined LST. And I’m gonna need some advise too. Scrog that’s what I wanna do, but CFL’s are good ur plants will grow. Mix ur CFL’s. 2700’s n 6500k’s mixed spectrum happy growing.


Did you use all of those at the same time? Or did you use the 6500k’s for your seedlings and veg cycles, and then switch to the 2700’s for flower.


The guys on here will know, I’m new…I wish i had 2 different grow boxes to run separate lights. I have a budget grow box and use all my cfl lights i can get A hold of.


A mixed spectrum is shown to have good results and many of us run 1000w bulbs which take up large space so using a mix is not always an option for us if you can mix spectrums by all means do a little more blue during veg a little more red during flower or even balance. It’s not that we wouldn’t benefit from mixing spectrums it’s just less feasible when using large vented hoods


sorry @Rfox19 wasn’t directed at you buddy just quoting that you did answer the question :wink:


No I just used 4 CFL’s but when they both sprouted that’s when I used 10. Yah I mixed them 5 2700k’s n 5 6500k’s. But I’m upgrading my grow lights this week, LED or HPS but HPS gets too hot idk bout the LED tho. Any advise on grow lights?


No problems I’m still learning n am a beginner also. I want to upgrade my lights too. I want to get a LED or HPS but I’m having trouble making up my mind. My last grow was awesome n fun n here I am growing 2 white widows I bought from cropking seeds, feminized seeds. Soon I’ll buy a grow tent right now I’m using the grow box I made, 1 box for Veg n later when I put them in 12/12 I’ll bring out the flower box. Any advise on grow lights? Donaldj?