OregonMeds
Well-Known Member
that couldn't be further from the truth. A hot spot is a wrinkle in the reflective material causing a convex shape that focuses the light. It is no different than using a magnifying glass to burn wood.
Common sense dictates using a ventilation system of some type...how can you get hot "air pockets" with air constantly moving?
THIS is what I mean be retards spreading rumors...I don't mean everyone is a tard...just the people who believe in something totally wrong and spread the incorrect information.
a so-so post. yea Mylar isn't THAT superior but plain ol every day flat white paint isn't in the same ball park with good reflective materials.
Getting dirty? What makes you think a painted surface doesn't get as dirty? I'm guessing it's because you can't SEE the dirt that you think it's not as dirty. Truth is, it doesn't matter what you use, it gets dirty at the same rate.
Flat paint? No, you should at least use an egg shell sheen. If you are using floros you should use a high gloss if possible.
If you want to use paint at all, buy a premium brand of roof coating (Cool Seal) which reflects about 95% of all light.
The problem with flat white paint is it reflects less than 70% of all light (key word here is ALL as the light you and I see is useless to plants). In reality, the thermal blankets (sold at most sporting goods stores in the camping section for $2.00) or the mirror like gift wrap reflect roughly 80% and are superior to flat white paint. I strongly suggest you only use these if you are using floros however.
Where I agree with this poster is I would take paint over mylar with HID lights. Where a wrinkle could cause a "hot spot" a painted surface won't.
Again I apologize for all the "retard" comments. I hate when I hear (on a forum or in real life) "I just read xxx is true dude! You should be doing that!" People don't take the time to find out the guy that posted xxx is a retard...and they become a retard as well for spreading the...well....tardness!
Actually urine is a great fert. It's sterile as well. Very high in Nitrogen, but the problem is it's too strong and as it decays it invites bacteria that wouldn't normally be attracted to your soil. Unless you have a perfect environment, I wouldn't recommend it either.
Well at least you found some of my info correct but you're way off on some things, so let me try to correct them:
Shiny paint (gloss or eggshell) has an additive in it to give that sheen. Just because you can see a shine doesn't mean it's more effective than flat, in fact quite the opposite.
The white in the paint is the only thing actually reflecting the spectrum. The light has to pass through the gloss first, then reflect off the white then reflect back through the gloss. You loose more light with any amount of gloss in a paint at all and it actally makes a pretty big difference. It's like light through a window vs straight light.
Plus gloss white hot spots as you said.
The difference between dirty mylar and dirty paint has simply to do with how much easier it is to clean or repaint the paint, and I suggested just repainting the paint as often as every couple grows. It's easy as hell to run a roller over a wall with some paint and no way in the world are you cleaning mylar that easily. If someone is I think we would all love to hear about it.
Beyond all this: One problem with mylar that I didn't even mention is it is directionally relective only and distributes light very poorly. Just as would happen trying to bank a ball in a game of pool a 30 degree incoming angle goes out at an equal 30 degrees. Usually that means a lot of your light directed exactly where it does no good at all. Figure out your angles. Additionally mylar is gray, automatically. If you understand how we see color you'd know that mylar isn't going to refect back as much light spectrum as white. What we see as color is the color that something ISN'T. That's the color that whatever you're looking reflects, and that reflected light is what's picked up by the eye. So essentially when you see green, it's every color except green, which is why you see green. White is no color. It absorbs nothing and scatters light evenly. The only loss from refected light off a flat white is the strength of the light. The spectrum is virtually unaltered.
There is ample evidence like what I said in the last two paragraphs that flat white may in fact be superior period in how it reflects light compared to mylar but that would have been too controversial and there is not enough scientific evidence of direct comparisons in grow situations that I'm aware of to support my taking a firm stand on that without having to argue that to death, so I didn't claim it at all originally but did now only to try and explain more of the how and the why.
Anything else anyone questions about this subject though I'll try to answer, but I'm no scientist I just happen to know a few things.
I think I will break this out into it's own thread tomorrow.. I'm tired now.
You can even add some very common additives to make flat white even more reflective than it already is, but that can be quite troublesome...
happy growing