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Good Idea or bad idea.
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Posted by collegegrower (My Page) on Wed, Dec 19, 07 at 23:19
well i was browsing the internet to see how to make flouros more efficient, and i cam across an article stating that using aliuminum tape on the top side of ur bulb is one of the best reflectors, i just wanna know is this true, i found this article on a pot grower website.
and i got a 8tube t5ho and couple t8s would the tape work on them or no??? |
Follow-Up Postings:
RE: Good Idea or bad idea.
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No.
The adhesive cuts down reflectivity.
What's your Daddy's phone number?
I am going to tell him that you are growing pot. :-) dcarch |
RE: Good Idea or bad idea.
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| ok what if i used mylar and just taped the ends? |
RE: Good Idea or bad idea.
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| o yea i dont grow pot, i grow salvia d. cucumbers watermelons native grasses and flowers, i would grow pot if it was legal lol. |
RE: Good Idea or bad idea.
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| You can actually buy fluorescent tubes with the top half silvered. I am uncomfortable with the whole concept, fluorescent tubes are not designed to have light passing through them and the extra heat buildup is not helpful. You can get metal halide lamps with the same kind of built-in reflector. Not quite such a problem there because the silvering is on the jacket rather than the actual arc tube. T5HO systems usually have pretty good reflectors, I don't think you'll improve things very much with tape, probably make it worse. Of course you can always try it and see. There's no substitute for actually measuring the light you get with various arrangements. Also, if I remember right you have a fully enclosed system so you aren't losing a huge amount of light anyway. |
Bad.
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If this method was more efficient, then we'd see it applied commercially. The commercial people (warehouse, stores, etc. are very conscious of lighting efficiency, and are constantly upgrading, in order to save costs. If they could save cost by doing that to increase their lighting efficiency they would. What you do see, and what I've done in my setup, is using specular reflectors in their fixtures, so what I do (it's a two person job, by the way), is to line the fluorescent fixture, the reflector part of it, with mylar. I use double sided 3M carpet tape, I put a strip down the middle first, attach the mylar, and then use a few small pieces of tape to hold it to the outer part of the reflector. I think that putting a reflector on the actual lamp will run into problems where the photons will collide with the phosphor on the opposite side and create a shadow.
So I'm with shrubs. Bad. Also, as shrubs says, you're moving the operating temperature outside of the optimum range and decreasing efficiency even further.
Paul Mozarowski. |
RE: Good Idea or bad idea.
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| ok thanks for the help so its a bad idea, but did test it out with my fish tank, and it defintaly made it brighter, o well ill listen to u guys. |
RE: Good Idea or bad idea. Me curious now.
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I wonder if the foil reflector you used is more effective than the stock reflector on your fixture. Many fixtures have very poor excuses for reflectors on them, and maybe what you suggest could be an improvement. So, instead of talking out of my hat, I moved my butt, and took a precut piece of mylar, 46"x10", and JUST DRAPED IT over the two lamps in my 1241cw shoplight fixture, and then I took my Hydrofarm Digital Footcandle Meter, and actually measured to see what happens: Results: guess what, the mylar drape works better than the mylar lined reflector, close to the lamps there is a nice uniform 4000 - 5000 footcandle intensity! compared to 3000 to 4000 footcandles for the mylar lined reflector. I would like to take back what I said in the previous post. Cut the mylar so that you can slip it over the top of the two tubes and let it hang over the edges of the tubes to catch the sideways light and let it shine downwards. Wow, with this intensity, you could grow some serious crops!!! Note: the above measurements were taken in the overdriven configuration. Even with normal drive though, the typical intensity was 3000 foot candles, which is what I was achieving previously just with overdrive. This is a definite improvement. Hats off to the stoner potheads!
Paul Mozarowski. |
RE: Good Idea or bad idea.
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| Paul, you may just be concentrating the light into a smaller area. Statement of the blindingly obvious I guess! But focussing all the light from a shoplight into a tiny space a couple of inches wide isn't very practical for growing plants :) But shoplight reflectors are never good enough for growing plants, they are designed to spread out the light, not to focus it straight down onto a small area. Also, they never come down far enough at the side of the tubes. Even if you don't add something touching the tubes, you should always add something coming down several inches lower than the tubes at the sides. |
shoplight reflectors
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Yes shrubs you're right, the mylar is probably concentrating the light more. When I fasten the mylar to the stock reflector, I actually allow an 1 1/2 inch extra on each side, that hangs down further than the stock arrangement, to improve the efficiency of the reflector. This 1241cw shoplight that I use is better than most in that its reflector is better than most, is both narrow and has a nice curve to it.
But in any case, draping the mylar over two tubes at least does not impede the light, and probably results in better efficiency that most standard shoplights, which have a terrible reflector built in. pm. |
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