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Two CFLs


New Member
Hello guys,

Just prepping for my new grow, I had one dual CFL 300W until now, which I used with a reflector.

I've bought another 300W CFL but now, it's only red. I'm thinking about using them together, as the earlier dual cfl has half the tubes red.

I've bought it to have bigger buds, as 300W only seems to produce 30-40g/run.

Now, I started to grow 4 autos and was thinking about how to position the lights.

I've got a hanger and two reflectors. So I guess the choice would be to hang the older light in the middle of these 4 plants, and the red at the top once it starts to flower ?

So the blue could improve side growing and the red the buds on top.

Also would love to hear other suggestions, I guess it's not a very good choice to just have both of them next to each other, since only two plants would get the power up from one cfl.

Ideas are strongly welcome!

Also, i've chosen CFL with a reason, don't tell me to buy a different type or model.



New Member
I generally dislike the large CFL bulbs for a number of reasons, but to give you a suggestion. Place the dual overhead until you upgrade the pot size and flowers start to show. Then place them both overhead and rotate the pots underneath halfway through the light cycle.

Don't forget to check out the links in my signature. One is basic lighting information and the other is for our member plant and nugget of the month competitions.


New Member
Thank you very much for the answer, now I know I should've gone with little CFLs but they make an excessive heat!

Also, I put in both CFLs and the heat is extreme. I guess i'll wait till the plants grown a little bigger, then have both of the CFLs installed. It was like 35 C inside the tent. Larger plants won't care, but seedlings can be killed with heat I guess.


New Member
35C is still a bit too hot for even larger plants. The heat is one of the main reasons I dislike larger CFLs. Florescent's are the least efficient of the allowable lighting types now. Which means the energy they are using that is not given off as light is given off as heat. One way of preventing the excessive heat is to increase the air movement in your grow area. Using a bottom in top out air exchange method will reduce your temperatures quite a bit and is much easier than attempting to cool the box. If the above isn't cool enough, you can place an air cooler close to your air inlet area.


Active Member
i grew with smaller CFL's before making the switch to MH/HPS. What i like about the smaller CFL's is the ease by which one can direct light to saturate the plants from every angle. I used upwards of 600W (real watts) which consisted primarily of 26 watt bulbs. Passive air flow using oscillating fans kept the temps just right. I still use them for side lighting. Would you consider 26 watt overheads?
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