Using Mirrors to reflect light ?

G

*. GaMbO .*

Active Member
Well i was reading a thread that said tin foil sucks to use in a grow box for light reflection . . they said to use poly or white wall . . it had me thinkin . . i could be just an idiot but wouldnt mirrors reflect the light the best . . mirrors on all sides of the box. I wouldnt think the mirrors would reflect the heat , only the light . Wat yall think.
 
closet.cult

closet.cult

New Member
I have read that mirrors do not 100% of the light that hits them. they steal some of the spectrum and should not be used. read more to be sure.
 
Jesushasdreads

Jesushasdreads

Well-Known Member
when you look in a mirror do you see 100% of your reflection? I've not looked into a mirror that made my reflection more dim than me. Mirrors reflect 100% of light that falls on them
 
closet.cult

closet.cult

New Member
Jesushasdreads said:
when you look in a mirror do you see 100% of your reflection? I've not looked into a mirror that made my reflection more dim than me. Mirrors reflect 100% of light that falls on them
Click to expand...
is this a thought experiment here, or have you actually used a light meter and a sprectrometer to verify this?

you are aware that not all spectrums are visable to the naked eye, aren't you?

this is the sort of question that requires research, not someone pulling an answer out of their ass.

the verdict is: everyone has thought about using mirrors in the grow space. and many sources recomend not to because they do NOT reflect the whole spectrum as well as foil or mylar or flat white painted walls. foil is a last resort, supposedly, but i dont personally regard the 'hot spots' as that big of a deal.
 
Jesushasdreads

Jesushasdreads

Well-Known Member
the answer is use the poly flat white paint or mylar for your growing as they are all proven methods of reflecting light. Mylar is more difficult to hang correctly that the poly and reflects more light but poorly hung mylar is no good. i would go with paint or poly if i were you...but that's my opinion
 
Jesushasdreads

Jesushasdreads

Well-Known Member
ok i am sooo sorry that the marijuana plants might not get ultraviolet and infared light but i have not ever seen where that spectrum is at all conducive. in theory a surface could polished to the point that it could reflect those wavelengths but to our visible eye, it would not matter. we dont see outside of the white light spectrum to my knowlege and i know that mirrors reflect 1
00% of the visible spectrum. is that what i should have said....mirrors reflect 100% of the visible spectrum of light?
 
Jesushasdreads

Jesushasdreads

Well-Known Member
yeah, i think hotspots are ludacris....i have used foil, mylar, and the black and white poly and not had any sort of hot spots
 
G

*. GaMbO .*

Active Member
im using foil right now . . most convient to just about anyone . . now if i were to use flat white paint . . could this be any kind of paint or a specific kind . . might be dumb but i am new to indoor growing . . if the foil will be fine then ill keep it . . i just read earlier that foil is not good so i began ponderin wat i could use . . someone told me the inside of chip bags is good to use also . . is this true ?
 
email468

email468

Well-Known Member
mirrors are perfect reflectors. Too perfect since they do create hot-spots. Don't believe me? Look into a mirror and shine a bright light into the mirror. Move the light around until it shines right into your eyes. That would be a hot spot and wherever it shines onto a plant it will burn it.

I said mirrors are perfect reflectors but they technically aren't since nothing is a "perfect" reflector. Every time light reflects there is some loss. So the light bouncing off a mirror has most all of its spectrum intact. Any material that absorbs light would have an affect on the reflected spectrum. And you can control specular reflectivity accordingly. Example: If you wanted mostly red light reflected, you would use a reflector that absorbed green and blue. The reflected light would have a higher than normal degree of red.

You don't really need a spectroscope to figure this out though - just a physics 101 book.

To answer your original question - don't use mirrors. hot spots are real.

If reflectance is what you're after, it is hard to beat properly hung mylar. But if durability, reflectance, cleaniblility and all-around usability are what you're after - then consider panda plastic.
 
closet.cult

closet.cult

New Member
any label has a cheap 'flat, white paint'. it reflect better then foil.

i've heard of using the inside of chips bags. i guess it would be like mylar. mylar reflect better then flat, white paint.
 
email468

email468

Well-Known Member
also note - foil has the same issues as mirrors - the crinkling can create hot spots. Flat white paint is a great surface for the inside of a grow box.
 
BIGMIKE13

BIGMIKE13

Well-Known Member
hope this helps...

Reflective Chart Material Reflectivity : Black less than 10% - Aluminium Foil 55-70% - Semi-gloss White Paint 60-70% - White / Black / White Film 70-85% - Flat White Paint 75-80% - Polystyrene Foam Sheeting 75-85% - Mylar Sheeting 90-92%
 
G

*. GaMbO .*

Active Member
well i found this tape laying around . . its not like aluminum foil but reflects like aluminum foil except it wont crinkle . . it looks like it will do the job good . Its called cold weather formula Venture Tape
 
EarthlyPassions

EarthlyPassions

Well-Known Member
Meh, I used aluminum foil that was just lying around the kitchen, worked just fine. No burning, no 'hot spots', and it's as crinkled as hell. Mirrors are heavy, expensive and breakable, the lack of convenience is enough a reason not to use them.
I don't think my plants are stretched either, they are a bit tall, but those are my males anyway. The females are nice and bushy.
 
I

InNeedOfWeed

Member
Wouldnt the hot spots also depend on the heat of the lamps? What if your using a florescent low heat lamp would it still be dangerous? What about when some people grow in winter wouldnt the extra warmth save on your electric bill?
 
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