Wrap Backs of CFL with Foil

I saw in a video where a CFL grower wrapped the back side of his bulbs with tin foil to reflect the light. Any thoughts on this?

I mostly worry about the risk of fire and electric conductivity of foil.. Besides that it seems like a decent idea.

sunny747 said:

I saw in a video where a CFL grower wrapped the back side of his bulbs with tin foil to reflect the light. Any thoughts on this?

I mostly worry about the risk of fire and electric conductivity of foil.. Besides that it seems like a decent idea.

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I've done it for the longest with no problems at all. I don't do it so much for the reflection though, I do it so the light isn't shinning all in my face.

some will tell you it's a bad idea because it will hold heat or create a hotspots, but again, never had that problem so...

Gary Goodson said:

some will tell you it's a bad idea because it will hold heat or create a hotspots, but again, never had that problem so...

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I have always said that "Hotspots" from using foil is just a myth; just one of those things that gets passed along. I have said, many times, nobody has actually had that happen - ever! The real reason not to use aluminum foil is because it is a relatively poor reflector.

Now, with that being said, anything you can do to save some of the light from escaping out the back side of your bulb is a good thing! Bye all means, use it!

T.H.Cammo said:

I have always said that "Hotspots" from using foil is just a myth; just one of those things that gets passed along. I have said, many times, nobody has actually had that happen - ever! The real reason not to use aluminum foil is because it is a relatively poor reflector.

Now, with that beings said, anything you can do to save some of the light from escaping out the back side of your bulb is a good thing! Bye all means, use it!

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Foil will retain heat.. probably not enough to do anything but please believe if u try to wrap a 432 watt t5 with foil it will transfer some noticeable heat.its not a myth it's a fact that foil will either retain or reflect heat...more so if it's attached to the object. It won't harm him in his situation because his cfls won't produce a lot of heat

I hear what you're saying about retaining heat - sure, the foil will absorb heat from the bulb. But, that is heat that "already exsists" - no high temperature "Hot spots" are actually being created.

What I'm disputing is "that crinkeled foil will focus and condense the reflected light into "Hotspots". Thereby amplifiing the temperature. It would be sort of like burning leaves with a magnifying glass, except that many,many of the crinkeled facets would have to focused at exactly the same point or area. I suppose that could possibly happen, but what are the odds? I would say one in several million-to-one.

Over the bulb is ok, you have to crinkle foil like hell and beam it with a ton of radiant energy to burn plants. Although i would any day recomend white paint for the grow room walls over foil, you dont want bouncing radio-waves on the side of you're canopy.


Also, foil WILL and i have tried increase the grow room temp. You are physically heating a metallic object, this object will emit radiant heat back into the room ect because of being able to reflect much more radiant energy. The heat has to go somewhere, without a boost in ventilation or air cooling the foil like sealed hoods, it will just reflect too much heat. White walls absorb heat much much more than foil/mylar, allowing the heat to travel to the external portion of the walls while reducing internal temps

If you even do have hotspots, if you just turn your plants even the slightest once in awhile it def wont be an issue. Especially CFL.

Have you had a look at beer can reflectors? Paint the inside white. Ghetto as f*ck but they will do a much better job and are a lot more durable than tinfoil

No reason to crinkle foil, thats just dumb..sorry

At most use the dull side of your foil..to spread light more evenly if you dont, nothing bad will happen..

I ran 750 watts of cfl in a little 2x2 mini grow. Worked great.

Foil in general is a pretty good reflector. I even use it outdoors to capture more sunlight on some of my plants as the sun moves across

Foil isn't going to cause appreciable hot spots, and reflects very well. the problem with foil is it make a ton of crinkling noise, and is hard to apply onto the walls. Other than that, it's a pretty good reflector. Noobs who do research tend to avoid aluminum foil, so there's a correlation between people who avoid foil and people who do their homework, but that correlation does not mean that foil is what causes noobs problems.

churchhaze said:

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Thats interesting how silver and gold peaks like that.