My roommate and i are discussing whether or not to put up sheets of mylar in our new grow set up we are about to build. He brought up a good point in saying that he has been told that if you do this and it is too reflective, that the heat and light will soon begin to damage the plant. Has anyone heard about this or have any experience?
Reflective Mylar
- Thread starter gk707
- Start date
GreenphoeniX
Well-Known Member
Use glossy or flat WHITE plastic instead. You can usually get it from anywhere you'd get mylar from. It's usually one side black and one side white, the black goes against the wall, and the white faces out so it reflects the light.
White is more reflective than a metallic surface, generates less - no heat, and won't burn holes in your plants off pointed bits like mylar of tinfoil is said to do on occasion.
White is more reflective than a metallic surface, generates less - no heat, and won't burn holes in your plants off pointed bits like mylar of tinfoil is said to do on occasion.
GreenphoeniX
Well-Known Member
Yip, that's the stuff mate. I use it too. Called Panda Plastic where I am, it's all the same stuff obviously haha.
GreenphoeniX
Well-Known Member
Depends how you want it. It's about $200 ($147.60 Canadian) for a roll 4 metres (13.12 feet) wide and 50 metres (164 feet) long.
potroast
Uses the Rollitup profile
Mylar is fine and will work well, if it is smooth with no wrinkles. The easiest and nearly as good is flat white paint.
Here's the chart of percentages of light reflected from Jorge's latest:
Foylon 94-95
Reflective Mylar 90-95
Flat white paint 85-93
Semi-gloss white 75-80
Flat yellow 70-80
Aluminum Foil 70-75
Black < 10
HTH
Here's the chart of percentages of light reflected from Jorge's latest:
Foylon 94-95
Reflective Mylar 90-95
Flat white paint 85-93
Semi-gloss white 75-80
Flat yellow 70-80
Aluminum Foil 70-75
Black < 10
HTH
GreenphoeniX
Well-Known Member
As long as you have a half decent reflective material, it means you're getting more out of your light(s) ... The rest is really up to personal choice, ease of use/installation, and how much you want to spend.
But to get the most out of your light, use Mylar, Panda Plastic or Foylon... Never used Foylon, but it sounds very good!
But to get the most out of your light, use Mylar, Panda Plastic or Foylon... Never used Foylon, but it sounds very good!
platypusmann
Well-Known Member
I like mylar. $17.95 for 50 feet. I used elastomeric paint in the beginning...with a presumptive reflectivity of 85%. I switched to mylar and I guarantee I increased reflectivity 25%...it is amazing.
However...I got some surfacant (fungicide disinfectant) onto the mylar (I use it on the wall underneath) and it turned the mylar completely see through in 24 hours. Fucking weird. Ate the reflective coating off. SO...I let the wall dry bettter before I hung the mylar the second time.
I never used panda plastic...after my grow tent (hydrohut) fiasco I am deathly afraid of shiny white surface....I had to throw away my soft side lucnh cooler because it had shiny white inside and I threw it away. I know it would turn my lunch yellow, then it would wither up, and then DIE.
However...I got some surfacant (fungicide disinfectant) onto the mylar (I use it on the wall underneath) and it turned the mylar completely see through in 24 hours. Fucking weird. Ate the reflective coating off. SO...I let the wall dry bettter before I hung the mylar the second time.
I never used panda plastic...after my grow tent (hydrohut) fiasco I am deathly afraid of shiny white surface....I had to throw away my soft side lucnh cooler because it had shiny white inside and I threw it away. I know it would turn my lunch yellow, then it would wither up, and then DIE.
The Martian
Active Member
Hi there All.
Potroast, do you know where he got his figures from?
I was always under the impression, that even a mirror is only around 82 84% reflective, and even a top quality Pyrex telescope mirror with all the expensive reflective multi coatings can only achieve 92 95%.
HHHMMMMmmmmm, have to do some checking on reflectivity.
OHHH wait a minute, no need, Platypusman has some new sectret kind of nano material, that actually INCREASES the light reflected off it, with a reflectivity of 110%, "guaranteed", he says "its amazing", it sure must be.
ha ha ha.
Potroast, do you know where he got his figures from?
I was always under the impression, that even a mirror is only around 82 84% reflective, and even a top quality Pyrex telescope mirror with all the expensive reflective multi coatings can only achieve 92 95%.
HHHMMMMmmmmm, have to do some checking on reflectivity.
OHHH wait a minute, no need, Platypusman has some new sectret kind of nano material, that actually INCREASES the light reflected off it, with a reflectivity of 110%, "guaranteed", he says "its amazing", it sure must be.
ha ha ha.
techhead420
Well-Known Member
Dielectric mirrors achieve greater than 99% reflectiviy in even cheap telescopes optics. They can actually surpass 99.99% in a narrow bandwidth.Hi there All.
Potroast, do you know where he got his figures from?
I was always under the impression, that even a mirror is only around 82 84% reflective, and even a top quality Pyrex telescope mirror with all the expensive reflective multi coatings can only achieve 92 95%.
HHHMMMMmmmmm, have to do some checking on reflectivity.
OHHH wait a minute, no need, Platypusman has some new sectret kind of nano material, that actually INCREASES the light reflected off it, with a reflectivity of 110%, "guaranteed", he says "its amazing", it sure must be.
ha ha ha.
Astronomy Technologies 1.25" 99% reflectivity dielectric mirror diagonal with compression ring eyepiece holder
Common mirrors have a low reflectivity because there's cheap glass in front of them. You're going through 4 transistions with different defraction charaterstics (light in to glass, glass to mirror, mirror to glass, glass to light out).
Mylar achieves such high reflectivity because it acts as a FRONT SURFACE mirror. This is a very important difference.
Here's a chart showing the reflectivity of a few material backing the claim of >90's% reflectivity.
Reflectivity - Wikipedia, the free encyclopedia
Here's the reflectivity plot of a special white paint in the high 90's% (barium sulphate added?):
http://www.astecpaints.com.au/energystar/downloads/not_just_a_white_paint.pdf
potroast
Uses the Rollitup profile
Thanks for that, I can't say anything about it better than that.
What this stuff should tell you is that reflectivity is of all light, most of which we don't see but our plants do. The idea that a common mirror will do a good job just shows that what may seem right to us actually isn't. The fact that flat yellow paint reflects better than aluminum foil, and flat white is better than glossy white should tell us that it's not common sense. The reflectivity also has to do with even dispersal of light, and that's where foylon is great.
And foylon is not shiny at all, it's like the dull side of foil.
HTH
What this stuff should tell you is that reflectivity is of all light, most of which we don't see but our plants do. The idea that a common mirror will do a good job just shows that what may seem right to us actually isn't. The fact that flat yellow paint reflects better than aluminum foil, and flat white is better than glossy white should tell us that it's not common sense. The reflectivity also has to do with even dispersal of light, and that's where foylon is great.
And foylon is not shiny at all, it's like the dull side of foil.
HTH
platypusmann
Well-Known Member
\OHHH wait a minute, no need, Platypusman has some new sectret kind of nano material, that actually INCREASES the light reflected off it, with a reflectivity of 110%, "guaranteed", he says "its amazing", it sure must be.
ha ha ha.
presumptive-based on presumption, probability, conjecture, hypothesis or belief
I am 110% certain I said I used paint with a presumptive reflectivity of 85%. That means I presumed, hypothesised, conjectured, and assumed that it was probable that the 85% reflectivity I was told of was an accurate figure. Ergo, since I had no factual basis for the 85%, I used the word presumptive.
When I added the mylar, I said I was certain I achieved 25% more light reflectivity. Therefore, my presumption of the reflectivity of the elstomeric paint was obviously wrong.
Martian, I apologize for using words above your level. Next time I will make sure I say "somebody done told me that this here paint was 85% reflective...and since I done got what I thunk was 25% more light out of this here melar stuff, I guess they tole me wrong."
Sorry for the mix up!
P.S. Having never used a light meter, I have always had to presume....so I am sorry I used the word guarantee...far too certain for guesswork.
P.P.S. And martian, I said a 25% increase from 85%......that is not 110%. 25% of 85 is 21.25%....SO.....I claimed a reflectivity of 106.25%....if we are splitting hairs.....and I am.
The Martian
Active Member
Hello all
OOOH man, where to start.
I'll do the fastest first.
Pot roast, the fact your staff and have been on here ages, evidently doesn't make you the genius you assume.
1), "What this stuff should tell you is that reflectivity is of all light, most of which we don't see but our plants do." ?????? what are you on about, which large band of frequencies exactly do our plants "see" that we don't?????, has'nt it been shown plants use very little infra red, and anything but very near ultra violet is harmful, is it not???
2), "The idea that a common mirror will do a good job just shows that what may seem right to us actually isn't. The fact that flat yellow paint reflects better than aluminum foil, and flat white is better than glossy white should tell us that it's not common sense.
HHMMmmm, I dont suppose your (in your own inimitable way) trying to inform us, that light follows quantum mechanical rules, and some aspects, while understanding how an experiment will turn out, cannot explain why, IE. lights wave particle duality?
Or is it that were just fick bastards, thus our assumtions must be wrong?
3), "The reflectivity also has to do with even dispersal of light".
Does it indeed????, where did you learn this "fact"??? when something disperse doesn't it spread/thin out?? not that I'm saying this is a bad thing for our purposes you undertsand.
OK Techhead, while on the face of it your response looks quite good, it seems their are a few small points need considering.
1), Yes your correct about a dielectrically deposited mirror surface, but as your quote says its dependent on wavelenght, and further your link is an advertisement, which turns on my scepticism from the start, this being a diagonal, the light has to pass through the optical substrate, that the mirror/dielectric is deposited on, is it not possible they're measuring total internal reflection, at the most opportune wavelenght, to "big up" the product,this product is hardly cheap, although granted its very good value, its mid priced amateur astronomy, just to be pedantic.
2), "Common mirrors have a low reflectivity because there's cheap glass in front of them. You're going through 4 transistions with different diffraction charaterstics (light in to glass, glass to mirror, mirror to glass, glass to light out)."
Righto, thats wrong, only partly due to the glass, and dont you mean REFRACTION? Diffraction is spreading, like the spectrum spreads out going through a prism, or off a diffraction grating, (a CD acts as a Diff grating due to the very small size/spacing of the rows of pits, thats why one can see the spectrum from a CD surface).
I think you meant, that light travels at a different speed through mediums of a different REFRACTIVE index, and does it "make four transitions"???
I'm not sure, the actual system would be, air to glass ????? reflect from mirror surface ????? glass to air, not sure its four, where are the other two transitions? and this would be unobservable if the incident angle was exacly 90 degrees to the plane of the surface.
Therefore.
3), "Mylar achieves such high reflectivity because it acts as a FRONT SURFACE mirror. This is a very important difference" this now has lost its "proof", what is your reasoning for this now??
BTW a typical telescope mirror is always "silvered"on its front surface, and is around the figure I posted earlier.
"Some of them use silver, but most are aluminum, which is more reflective at short wavelengths than silver. All of these coatings are easily damaged and require special handling. They reflect 90% to 95% of the incident light when new." ref Wikipedia.
4), "Here's a chart showing the reflectivity of a few material backing the claim of >90's% reflectivity." Does it indeed???
It seems your partial to posting links as your "proofs" without actually reading/understanding them.
Reflectivity and Reflectance are NOT the same thing, and guess what?????
your "proofs" are all reflectance measurements.
Doesn't really back the claims after`all does it.
5), Did you not notice that in your last link, your white paint reflectivity plot "proof", was also Reflectance???, and that it was claiming a so called "Reflectivity" for the bog standard white paint of from 82 to 89% from 400 to 1100 nm which BTW is from mid violet right up well into infra red.
You really should start READING the "proofs" that you post more carefully.
I was merely asking if anyone knew how reliable his figures were, as I've seen these lists before, and I'm pretty sure that the different materials are being measured in slightly different ways, IE, shiny materials measured with specular reflectivity, and flat/matt materials measured with diffuse reflectivity, possibly all the materials measured differently, and its pretty obvious that you have trouble differentiating between similar measures.
And platypusman, it was a JOKE, on an obviously wrong simple mistake, and I was unaware that presumptive reflectivity, was a recognized measure.
you "in the same line, quote a presumed 85% and then "guarantee" a 25% improvement, so although youve managed to get something to over 100%, were to believe the "guaranteed" bit.
Come on, does this not seem the slightest bit funny, for folk who smoke, you've the poorest senses of humour I've come accross.
I look forward to hearing your responses, constructive of course....
Tatty Bye All
OOOH man, where to start.
I'll do the fastest first.
Pot roast, the fact your staff and have been on here ages, evidently doesn't make you the genius you assume.
1), "What this stuff should tell you is that reflectivity is of all light, most of which we don't see but our plants do." ?????? what are you on about, which large band of frequencies exactly do our plants "see" that we don't?????, has'nt it been shown plants use very little infra red, and anything but very near ultra violet is harmful, is it not???
2), "The idea that a common mirror will do a good job just shows that what may seem right to us actually isn't. The fact that flat yellow paint reflects better than aluminum foil, and flat white is better than glossy white should tell us that it's not common sense.
HHMMmmm, I dont suppose your (in your own inimitable way) trying to inform us, that light follows quantum mechanical rules, and some aspects, while understanding how an experiment will turn out, cannot explain why, IE. lights wave particle duality?
Or is it that were just fick bastards, thus our assumtions must be wrong?
3), "The reflectivity also has to do with even dispersal of light".
Does it indeed????, where did you learn this "fact"??? when something disperse doesn't it spread/thin out?? not that I'm saying this is a bad thing for our purposes you undertsand.
OK Techhead, while on the face of it your response looks quite good, it seems their are a few small points need considering.
1), Yes your correct about a dielectrically deposited mirror surface, but as your quote says its dependent on wavelenght, and further your link is an advertisement, which turns on my scepticism from the start, this being a diagonal, the light has to pass through the optical substrate, that the mirror/dielectric is deposited on, is it not possible they're measuring total internal reflection, at the most opportune wavelenght, to "big up" the product,this product is hardly cheap, although granted its very good value, its mid priced amateur astronomy, just to be pedantic.
2), "Common mirrors have a low reflectivity because there's cheap glass in front of them. You're going through 4 transistions with different diffraction charaterstics (light in to glass, glass to mirror, mirror to glass, glass to light out)."
Righto, thats wrong, only partly due to the glass, and dont you mean REFRACTION? Diffraction is spreading, like the spectrum spreads out going through a prism, or off a diffraction grating, (a CD acts as a Diff grating due to the very small size/spacing of the rows of pits, thats why one can see the spectrum from a CD surface).
I think you meant, that light travels at a different speed through mediums of a different REFRACTIVE index, and does it "make four transitions"???
I'm not sure, the actual system would be, air to glass ????? reflect from mirror surface ????? glass to air, not sure its four, where are the other two transitions? and this would be unobservable if the incident angle was exacly 90 degrees to the plane of the surface.
Therefore.
3), "Mylar achieves such high reflectivity because it acts as a FRONT SURFACE mirror. This is a very important difference" this now has lost its "proof", what is your reasoning for this now??
BTW a typical telescope mirror is always "silvered"on its front surface, and is around the figure I posted earlier.
"Some of them use silver, but most are aluminum, which is more reflective at short wavelengths than silver. All of these coatings are easily damaged and require special handling. They reflect 90% to 95% of the incident light when new." ref Wikipedia.
4), "Here's a chart showing the reflectivity of a few material backing the claim of >90's% reflectivity." Does it indeed???
It seems your partial to posting links as your "proofs" without actually reading/understanding them.
Reflectivity and Reflectance are NOT the same thing, and guess what?????
your "proofs" are all reflectance measurements.
Doesn't really back the claims after`all does it.
5), Did you not notice that in your last link, your white paint reflectivity plot "proof", was also Reflectance???, and that it was claiming a so called "Reflectivity" for the bog standard white paint of from 82 to 89% from 400 to 1100 nm which BTW is from mid violet right up well into infra red.
You really should start READING the "proofs" that you post more carefully.
I was merely asking if anyone knew how reliable his figures were, as I've seen these lists before, and I'm pretty sure that the different materials are being measured in slightly different ways, IE, shiny materials measured with specular reflectivity, and flat/matt materials measured with diffuse reflectivity, possibly all the materials measured differently, and its pretty obvious that you have trouble differentiating between similar measures.
And platypusman, it was a JOKE, on an obviously wrong simple mistake, and I was unaware that presumptive reflectivity, was a recognized measure.
you "in the same line, quote a presumed 85% and then "guarantee" a 25% improvement, so although youve managed to get something to over 100%, were to believe the "guaranteed" bit.
Come on, does this not seem the slightest bit funny, for folk who smoke, you've the poorest senses of humour I've come accross.
I look forward to hearing your responses, constructive of course....
Tatty Bye All
platypusmann
Well-Known Member
Now sir, I do feel you have taken my rebuttal as a personal attack, and for this I beg your defference. It is easy to assume that since you know so very much about growing weed and know so very much about reflectivity, I should not be trying to bang heads with you...I will surely lose.
I was merely stating that the paint I used had a presumptive reflectivity of 85%, meaning this is what was presumed, but never verified or tested. Sorry that I did not again make this clear.
I again must make note that I apologized for saying guaranteed...I need to buy a light meter to provide a guarantee. Sorry for that...but my neked eye definitely sees that the room I lined with mylar traps light far better, therefore it must send it back somewhere, and I assume it goes to my plants, than the room painted with elastomeric paint, a paint I was turned on to by a roofer, not a grower, and whose reflectivity I can only presume based on what 1 person told me (the guy who gave me 5 gallons free), therfore I made the statement that obviously disconcerted you (awfully upright and argumentative for a smoker, aren't we) and made you feel it necessary to pick at what I said, although I did see you meant it to be funny. I agree, bad math is funny.
I again apologize that I do not meet your high standards of excellence on this sight, and that I have the poorest sense of humor of any smoker you've come across. That hurts, aww gee it do.
Honestly, I was just answering because I felt ignorant and wanted to clarify my post. Ignorance is something I freely admit.
Anyway, I come on this sight to learn and to share knowledge to help people...not to bicker, fight, and condescend. I grow weed because of a medical condition, and I forget that alot of people do it for personal gain.
I am here simply to learn and sharwe...not to attack and denegrate.
I pray peace for you, dear friend, and some day perhaps if our paths cross in person, you will agree with many folks who tell me I am the funniest mother fucker they know, but that would also mean I would condescend to hang around a douche bag like you, which I doubt I ever would.
Walk with light, my brother...you need it.
B
P.S. And no, I think it is funny that you interpreted my use of presumptive as certain enough to add the 25% increase I guaranteed to it. This is just plain ignorance. I presumed 85%....guranteed a 25% increase...therfore, since 106.25% is not possible reflectivity, an intelligent person would recognize my presumtion was wrong and I was stating that my increase from the mylar proved this. It is funny that you can't use english or do math....you must have gone to school in America, huh???
P.P.S. Now, since I am at work (work-to exert oneself by doing mental or physical actions for a purpose or out of necessity, to be employed) I must go now. Don't know why I am even wasting my time, but I just really dislike teenagers who feel the need to insult and attack people for no reason. You voted for Bush, didn't you???
I was merely stating that the paint I used had a presumptive reflectivity of 85%, meaning this is what was presumed, but never verified or tested. Sorry that I did not again make this clear.
I again must make note that I apologized for saying guaranteed...I need to buy a light meter to provide a guarantee. Sorry for that...but my neked eye definitely sees that the room I lined with mylar traps light far better, therefore it must send it back somewhere, and I assume it goes to my plants, than the room painted with elastomeric paint, a paint I was turned on to by a roofer, not a grower, and whose reflectivity I can only presume based on what 1 person told me (the guy who gave me 5 gallons free), therfore I made the statement that obviously disconcerted you (awfully upright and argumentative for a smoker, aren't we) and made you feel it necessary to pick at what I said, although I did see you meant it to be funny. I agree, bad math is funny.
I again apologize that I do not meet your high standards of excellence on this sight, and that I have the poorest sense of humor of any smoker you've come across. That hurts, aww gee it do.
Honestly, I was just answering because I felt ignorant and wanted to clarify my post. Ignorance is something I freely admit.
Anyway, I come on this sight to learn and to share knowledge to help people...not to bicker, fight, and condescend. I grow weed because of a medical condition, and I forget that alot of people do it for personal gain.
I am here simply to learn and sharwe...not to attack and denegrate.
I pray peace for you, dear friend, and some day perhaps if our paths cross in person, you will agree with many folks who tell me I am the funniest mother fucker they know, but that would also mean I would condescend to hang around a douche bag like you, which I doubt I ever would.
Walk with light, my brother...you need it.
B
P.S. And no, I think it is funny that you interpreted my use of presumptive as certain enough to add the 25% increase I guaranteed to it. This is just plain ignorance. I presumed 85%....guranteed a 25% increase...therfore, since 106.25% is not possible reflectivity, an intelligent person would recognize my presumtion was wrong and I was stating that my increase from the mylar proved this. It is funny that you can't use english or do math....you must have gone to school in America, huh???
P.P.S. Now, since I am at work (work-to exert oneself by doing mental or physical actions for a purpose or out of necessity, to be employed) I must go now. Don't know why I am even wasting my time, but I just really dislike teenagers who feel the need to insult and attack people for no reason. You voted for Bush, didn't you???
calicat
Well-Known Member
Mylar if the sheets are not perfectly placed on the walls makes bends and crevices. Those bends and crevices when light bounces off them are like mirrors on a magnifying glass that cause light damage to your plants. Mylar is also difficult to clean. I myself use panda film. The best reflective properties out in the market is a product called foylon..very expensive and I have never used it before so I could not give you input if they have a high maintainence.