Perfect, thank you! I already have one of those lamps lying around. I only have two small jades, should be getting a third on a trade soon, and a tiny sans pup. Might squeeze a small Hoya under there too, but this is perfect. I could probably also sneak these into my floor lamps too. Thanks for the advice, I will double check my lamps to make sure they are ok. Where could I find these, would they be at box stores or do I need to order them online?

I managed to find one at a local big box store (probably Home Depot). *If* I can still find the bulb, maybe I can take some light measurements at home for a general idea of how good they would be.

If you use a floor lamp, just make sure the light is pointed at your plants. Needs to be very close to be effective. Depending on your current light, it might be a good idea to adjust them slowly to the new light (65W CFLs are pretty bright).

Mine wasn't used for growing, but rather a tiny bathroom with crazy wallpaper. On the cheap, at least I think it should be pretty decent. =)

Update: I found my bulb. It is a T4 CFL, 40W, 4100k, CRI>60 by Blue Planet. Assumingly, a 6500k bulb would give slightly higher numbers.

Based on some quick measurements, the brightest spot is the middle of the side of the bulb. Which makes sense, because that is where there are the most coils/surface area.

Here are my instantaneous DLI measurements with a bare bulb (at the middle of the side):

• 15.5 @ 3"
• 12 @ 5"
• 2.65 @ 10"

And with a plastic tub as a 'reflector' (sorry my bulb didn't fit in any of my fixtures with reflectors):

• 19.75 @ 3"
• 15.5 @ 5"
• 4.8 @ 10"

And just for curiousity's sake, bare bulb from the top (vertical above plant):

• 7 @ 3"

Of course, the ideal location for your plant is where your reflector has focused the most of it's light.

Summary: Plants at 5" away of a 40W CFL in a lamp with a reflector from sunrise to sunset is a DLI of about 10, which is like bright shade.

Keep your plants close, as light intensity drops off quickly (with CFLs and all lights). Cheers!

How close is close enough? Like, if the light was on the ceiling (8 feet) and the plants on a 3 foot high table, is that close enough or two far?

Kim - I think that would be too far. My guess is that the light should be somewhere between 3" to 24" away from your plant. You will likely will need to slowly move it closer over time (or slowly increase time with the light on at a set distance).

A rough guideline is that light loses half its intensity with every 12" increase in distance. I teach this in my photography classes, where light is just as important. With my CFL bulb at 60" away, the light intensity is 1/4 of what it is at 12" away (aka. my light meter agrees).

A more practical way of saying this is that your light bulb gets half as good at growing plants every 12" further you put it. At 5" away the light may be like partial sun, but 60" it's more like full shade.

Hopefully that makes a bit more sense than my previous post!

It does, sorry if I didn't read it thoroughly, studying for an ecology exam. :) This information is fantastic, and super helpful. Nice to get academic insight. I was afraid this would be the case. For now, I will use the first approach as it is easier for me, the other I would likely have to hang chains from the ceiling, and I rent this place. Getting extra floor lamps for the CFL bulbs would help, and I do have a place where I can probably set up a little succulent/baby Hoya table for the winter. I want to move stuff outside in the summer, but I have a combination of crazy hyper canine and high traffic neighborhood with passersby who aren't always ah, considerate of residents to consider outdoors. But, I have blazing hot western windowsills for the summer too. So there is that!

Hi,

I'm sorry to post on someone else's thread, I can't figure out how to private message.

EWWMAYO could you possibly take a look at these pictures-I am not sure if one of these would be good to use. The 65 watt is labeled as a photography lightbulb, so it's throwing me off a bit. One is 40watt, 150 watt equivalent, 6500k and the other is 65watt, 300 watt equivalent, 6500k (the "photography" lightbulb).

I have no problem with threads changing around a conversation, and hope someone can answer this. Wish I could help with the PM problem, you have to go into your settings and make it so you can receive those I believe and I forget how. If you don't get a response, try posting this as a separate thread, if it is "fresh" it might get more attention. Good luck!

Thanks for not minding and good idea, I'm just going to make a new thread!

I've noticed some CFL's seem to cook themselves when they're in a small light fixture. Either that or the bulbs were very poor quality. The circuitry in the base of the bulb might break because of too much heat trapped by a snug fixture. I'd try to find a fixture that isn't a tight fit for the bulb. A fixture with some vent holes in the top would be good, too. Also, I noticed the spiral bulbs can kill fungus gnats.