W/ft^2? & best CFLs for growing?

Currently I'm growing a habenero in a pot, indoors along with about 8 herbs. I just got the herbs, so before I had my 3800 lumen (60w?) compact flourescent coil for my habenero only, which seemed okay. Now I'm getting a lot of flowers dropping, and I recently got the herbs, so I think I want to get another light. What is a good choice for like 20-30 bucks? I'm in a college apartment that's like 600 sq. feet so I don't have a lot of space..

Also, I've seen a lot of people referring to watts per Sq foot. That doesn't make a lot of sense to me because watts depends on how many lumens the light gives as long as it's in the right wavelengths. Can someone explain that to me?


This is what I have right now before I organize it. (I just repotted the herbs)

your right, you should not compare based on wattage, different technologies have different efficiency (lumens per watt) so throws everything off. One way you can increase the lighting is add reflective material around your plants. (cardboard box + alum foil college budget lol)
 
But yeah you can start comparing all the bulbs if you want, Make sure your comparing lumens/watt not watt-equivalence.
14w = 800 lumen = 57 lumen/watt
23w = 1600 lumen = 69 lumen/watt
42w = 2800 lumen = 66 lumen/watt
so seems the 23w is most efficient.
 
ALSO you can look at LED bulbs, they are good. example 1 or such 2
Can't compare the watts because it uses blue / red light to focus more on PAR(see faq).

Yeah I've seen a bunch of stuff about LED red/blue lights & PAR, although its hard to compare the equivalence to a light bulb because it is hard to compare specific wavelength amounts.

I thought about the cardboard box but I like actually being able to see the plant and not having it in a ghetto box/"greenhouse" lol.

30-50 watts/square foot of plant canopy attempts to compensate for different lumen output in lamps.

willard3 said:

30-50 watts/square foot of plant canopy attempts to compensate for different lumen output in lamps.

Click to expand...

What do you mean compensate for different lumen output? lumen/watt varys hugely in bulbs, so i guess I understand, but it's very inaccurate.