
CFL – Compact Florescent Lamp
CFL’s are a good, inexpensive, and energy saving alternative to HPS or MH growing lamps. They’re especially good for growing in small spaces like PC cases or smaller cabinets where even a small HPS would cook your plants.

This picture courtesy of micro.grower. Thanks micro!
They also work fine for larger grow areas, for larger plants. You just need more lights.
CFLs come in all shapes and sizes and are most beneficial in smaller places like PC cases because the smaller the bulb and wattage, the better the lumen output. (And a large 125w bulb wouldn’t fit in a PC case.) While a large 250w bulb will emit xxx amount of lumens, a smaller bulb will emit only xx amount of lumens, but percentage wise, the smaller bulb’s lumen output is higher. This fact should be carefully considered when adding CFLs as “side lighting.”

The color temperature (Kelvin) of the CFL bulbs is very important.
Easy Rule:
6500k (Daylight, also referred to as Blue) = Vegetative cycle
2700k (Soft / Warm, also referred to as Red)= Flowering cycle
Although,
Your plants will grow under all 6500k bulbs, or all 2700k bulbs.
Your plants will flower under all 6500k bulbs, or all 2700k bulbs.
Using all 2700k bulbs for veg will give you slightly slower, less vegetative growth, less lushness. But she’ll thank you during flowering.
Using all 6500k bulbs will give you lush green and abundant vegetative growth, but will hinder or slow down bud development and could possibly have a negative effect on yield.
You can start off using 6500k from seedling till the end of the vegetative stage, and then exchange them for 2700k. Or use a mix of both spectrums from start to finish…. Mix and match at will. But remember the Easy Rule and your plants will be happiest.

Seedlings love CFLs. They can climb right up to them and if you’re using smaller bulbs, there’s very little danger of burning them. The leaves will wither and probably turn brown and die if they are allowed to touch the bulbs. Never leave young plants unattended for longer periods of time with the lights close! After the fast vegetative growth (autoflowering plants) has stopped, you can get the lights in real close.

The positioning of the lights is another very important aspect. I’ll let the pics tell the story:
Improper placement can be a waste of good wattage.
A good reflective material is always a plus.
The glass part of the CFL bulb is much cooler than the ballast. The ceramic/plastic parts; that's where the heat comes from and it is a very good idea to have circulation around this part of your setup.

Here are a few resources for setting up an easy CFL rig:
Andy Botwin made this:
Find that article here---> https://www.autoflower.org/authors/andybotwin-2192/
My adaptation of Andy’s setup:

Get them while they're hot, folks- LED's are taking over quick!
:smokebuds:
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