Are Mirror's useable for reflection? Found 2 full sized bathroom mirrors in garage. 4' x 5'. Can I use these in my growroom with out killin my plants. Never used one but I dont wanna give them any burns.
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MIrror's
- Thread starter glasspackedbowl
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G
Guest
They are usable, but they are at the bottom of the list as far as effectiveness. I believe the reflectivity of mirrors is only around 55%. You'd be better off covering the mirrors with flat white paint, paper, or mylar. You'd even get more light from tin foil.
55% is plenty Im planing on going with Mylar. Cant get the cash at the moment. So I'll take it. See I went from a 400w Agro bulb 58,000 enhanced HPS to a 400w Philips reg HPS. So that 55% will make the diff. and save my some $$
G
Guest
I was involved a few yrs back in a 3 bedroom grow with wall to wall mirrors and 6 600's to a room......I never noticed any negative effects like burning but I've had better luck with mylar and it's so much cheaper. plus it sucks when liquid nails loosens up and the mirror falls and kills babys......stick with mylar
I did a search and found nothing about how reflective things are. Too much crap about mirror's that wasnt a mirror. Like programs and all sorts of crap.
Remember I dont have the mylar and I do have the mirrors.
Dr.D have you personally experienced hot spots are did u read that somewhere? I think its a big roomer. LIke the one about tin foil causeing hot spots. maybe im wrong.
Remember I dont have the mylar and I do have the mirrors.
Dr.D have you personally experienced hot spots are did u read that somewhere? I think its a big roomer. LIke the one about tin foil causeing hot spots. maybe im wrong.
Hi gpb i read it some where and it seems logical to me that it would...if this makes sense il explain best i can, when reflective materials like mylar reflect it throws the light in all directions obviously this makes it highlly effective..i think mylar is around 97%reflective...mirrors on the other hand seem to concentrate that light into a smaller area whilst absorbing a good amount of that light...thus creating a hot spot...try it out for yourself put a mirror in front your HPS and leave it a while and also look at the way the mirror reflects the light and feel around for hot spots..tho the hotspot thing may be caused by mirrors reflecting the light and another mirror..if you get what i mean..peace
G
Guest
I think that the hotspots thing has been disproven, but I haven't run the experiment myself.
The problem is that the glass absorbs much of the light and the silvering on the back of the mirror is not a perfect reflector; it does not reflect everything. As I said, go ahead and use the mirrors, but cover them with some white paper and you'll get more reflection. Recycle some junk mail by taping sheets together (plain white side out, of course).
Much better, if you can afford $2, go to Walmart and get an emergency blanket out of the camping section. These are thin mylar that are quite reflective for the cost ($2 each). Stretch some of this over the mirrors or sheets of cardboard and use them as movable walls. (Tip: when covering a mirror, cover the back side & tape to the front side. Tape will remove the mirroring on the back when it is taken off, so it's better to adhere the tape to the glass. Tape also sticks better to the glass than to the mirroring paint.)
The problem is that the glass absorbs much of the light and the silvering on the back of the mirror is not a perfect reflector; it does not reflect everything. As I said, go ahead and use the mirrors, but cover them with some white paper and you'll get more reflection. Recycle some junk mail by taping sheets together (plain white side out, of course).
Much better, if you can afford $2, go to Walmart and get an emergency blanket out of the camping section. These are thin mylar that are quite reflective for the cost ($2 each). Stretch some of this over the mirrors or sheets of cardboard and use them as movable walls. (Tip: when covering a mirror, cover the back side & tape to the front side. Tape will remove the mirroring on the back when it is taken off, so it's better to adhere the tape to the glass. Tape also sticks better to the glass than to the mirroring paint.)
Btw those emergency blankets have plastic in them too and they are flammable..at least iv just found out the ones they sell here in the UK are...i kno some people that had been using them..
experiment with the mirrors man and see what happens i remember doin these experiments in high school, i was under the impression that the mirrors can act like a magnifying lense try it out is the only way to find out for yourself.
experiment with the mirrors man and see what happens i remember doin these experiments in high school, i was under the impression that the mirrors can act like a magnifying lense
try it out is the only way to find out for yourself.
blackfin
Member
mirrors do consentrate heat... i had one of those mirrors that you put on the back of your closet wall and a friend and i took it outside one time and he shine it right at me reflecting the sun and it was hot!!!
why dont you just use white paint a gallon is really cheap and it's like 80% refl
but i know what you mean about being broke and your not reflecting the sun so give it a try
what color are the walls that you put the room in?
and sleepy had a good idea, when you get the cash put those babies on the ceiling over your bed
why dont you just use white paint a gallon is really cheap and it's like 80% refl
but i know what you mean about being broke and your not reflecting the sun so give it a try
what color are the walls that you put the room in?
and sleepy had a good idea, when you get the cash put those babies on the ceiling over your bed
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thanks guys. Im sure people will use this info. Facts put together say more the hear say. So i appriciate this info.
G
Guest
The growroom design faqs on OG discuss mirrors. "Mirrors waste energy by reflecting only a small fraction of the light that falls on them.
When light, which, like radio waves, is a form of electromagnetic radiation, strikes a metallic mirror the electrons in the metal move just as they do when a radio signal strikes an antenna. Pushing electrons around takes energy, which dims the reflected image.
Metallic mirrors reflect infrared light (heat) and if your mirror has imperfections this will cause hot spots, which can burn plants. Please note hot spots also apply to Mylar and Foil and IMO are not applicable to growers using small amounts of fluorescent lighting.
By using a mirror to reflect your light on a wall, you can test for imperfections, if you see an uneven image, with focused beams (normally located at the edge of the reflected pattern) these are known as hot spots and depending on the wattage of your bulb, may burn your foliage.
Metallic mirrors should not be used as a reflector for your grow room as minimizing light loss is important."
Believe it or not, mirrors absorb quite a bit of the light energy.
In documented tests they found Flat Titanium White paint to be about the best as far as reflective properties. Close to dimpled aluminum I believe, and far better than mylar or panda - which surprised me. 
That noted, I had a shed grow once that had 2 mirrors in the corner - I noticed the plants did well with no burning, unfortunately I was Noob enough to just leave it rather than paint the area (it was under a workbench). I later learned that had I painted it they would have finished faster.
More info on mylar and plastic reflective properties:
http://www.overgrow.com/growfaq/1567
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I fail to see how paint can reflect more then 90% back into the grow. ITs white but it hardly seams to reflect anything. The room is a white and I know im not getting any reflection. Simply because I moved recently and the old house had white paint and Im am yeilding the same here and the closet is yellow. I dought yellow reflects as much as white would. I so going with mylar or panda film.
Sunfilm Ultra
The ultimate reflective film that is 97% reflective. This film is extremely durable–puncture and tear resistant. Nylon mesh scrim reinforcement is woven into the film and is washable as well as waterproof.
if i had the cash this is it. $89.99
I dought yellow reflects as much as white would. I so going with mylar or panda film. Sunfilm Ultra
The ultimate reflective film that is 97% reflective. This film is extremely durable–puncture and tear resistant. Nylon mesh scrim reinforcement is woven into the film and is washable as well as waterproof.
if i had the cash this is it. $89.99
Well you cant always believe what you read [ especially stoner faq's at overgrow. ]
Mylar film facts.
-- anywhere from 5-10% more reflective than any kind of paint
-- highly flamable, what petroleum based plastic isnt? A costume made from saran wrap and safety matches would be less flamable. [ burn a small piece and see how much resistance it puts up.]
-- highly electrical conductive. Think of it as a wet puddle on a sheet. It has the same conductive properties as does a bare copper wire. [ a multi-meter check will show you zero ohms drop when you touch the probes to the mylar surface. Same as when you touch the probes together.]
Theres only one thing more reflective than mylar and thats Baader Astro Solar Film for making sunshields for telescopes. The only bad part is it seems to absorb UV instead of reflect it.
Mylar film facts.
-- anywhere from 5-10% more reflective than any kind of paint
-- highly flamable, what petroleum based plastic isnt? A costume made from saran wrap and safety matches would be less flamable. [ burn a small piece and see how much resistance it puts up.]
-- highly electrical conductive. Think of it as a wet puddle on a sheet. It has the same conductive properties as does a bare copper wire. [ a multi-meter check will show you zero ohms drop when you touch the probes to the mylar surface. Same as when you touch the probes together.]
Theres only one thing more reflective than mylar and thats Baader Astro Solar Film for making sunshields for telescopes. The only bad part is it seems to absorb UV instead of reflect it.
>... because I moved recently and the old house had white paint and Im am yeilding the same here and the closet is yellow. I dought yellow reflects as much as white would. <
Hiya gpb - actually if you are using an HPS in that room yellow would be almost as good a reflector as white - so I'm not surprised you didn't notice much difference. If you wanted to try an experiment, paint the walls blue and do a grow - betcha there'd be a big difference.
I'm such a stoner, I've lost the thread reference to this idea and don't remember the member's name who should get credit. If you want more light spread around, why not add a few cheap 40 watt spiral flourescents in amoung the plants on cheap straight lamps ( or hang 'em by their power line from the ceiling )? I would think that would provide more effective light than the difference between white walls and high reflectivity coverings. I started this in my flower cab a few weeks ago to try to beef up the lower bud sites. Might be cheaper than high quality reflector materials.
Just an idea - Happy New Year! -MGJ
Hiya gpb - actually if you are using an HPS in that room yellow would be almost as good a reflector as white - so I'm not surprised you didn't notice much difference. If you wanted to try an experiment, paint the walls blue and do a grow - betcha there'd be a big difference.
I'm such a stoner, I've lost the thread reference to this idea and don't remember the member's name who should get credit. If you want more light spread around, why not add a few cheap 40 watt spiral flourescents in amoung the plants on cheap straight lamps ( or hang 'em by their power line from the ceiling )? I would think that would provide more effective light than the difference between white walls and high reflectivity coverings. I started this in my flower cab a few weeks ago to try to beef up the lower bud sites. Might be cheaper than high quality reflector materials.
Just an idea - Happy New Year! -MGJ
I agree with ya on that white yellow thing. I used to do that. My plan is to covor the floor in plastic panda film, cover the walls with mylar, and use 4' fluro tubes in the 3 corners of the closet. maybe use some of the 20w cPT Fluro's I have. I just need the sockets, I had some that plug into outlets but lost thoses in the house in the big move. I did notice a difference in yeild at my old grow place with the use of fluros. They work wonders. Best for veg and extra lumination.
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Wow - didn't realise you already had those light add-ins! Sounds great man. Between the panda, mylar, and the flouros you'll be crankin out the buds! 
