Grow Box Interior ~ MYLAR VS. WHITE PAINT

So what's the opinion out there?

• Is mylar better than white paint?

• If so, what material do you use? I was considering buying several of those "mylar space blankets" at a camping store.

I am building a NGB box according to the plans in the forum but with a few slight modifications. Probably increase the diameter of the intake and build it taller.

If I decide to use mylar, I will probably coat the interior plywood with paint anyways to provide a better surface for the glue to adhere to.

Look forward to the responses.

Mylar is Better than white paint- 98% reflection.

White Paint- Around 85-90%

Which ever is cheaper

The space blankets aren't a good source of mylar as I understand. The rip easily and get crinkled very easily. White paint is easy and reflective, so I chose that. You can get rolls of actual mylar that is the correct thickness on ebay.

The efficiencies are so close it does not matter. IMO it boils down to whats easiest.

latex flat ceiling white, two coats. let the first coat dry completely before applying the second coat.

id say go with paint.

mylar can be a pita to install nicely in a confined space i found. paint is cheap and and easy to wipe down

I know it wasn't a choice, but I use 6 mil white plastic. I used mylar for my first grow, which was in a cab. Then I got mites on my third grow. In order to get rid of the mites, I needed to clean EVERYTHING. Mylar is slightly porous, so it needs to be replaced. White plastic can be wiped down with Simple Green or some other safe cleaning product. The reason that I bring this up is that effectiveness is only one consideration.

Reflecting as much light back onto your canopy is great, and reflective materials will help you do this. Ease of installation, cost of replacement, method of hanging, etc, are all things that are equally important, yet different for everyone.

The Inverse Square Law is something that comes into play here. If you DOUBLE the distance between a light source and an object (say, your canopy) , it becomes 1/4 as powerful. In other words, if your lamp is centered 6" above your canopy, but 12" from the side walls of your grow cab, then the light that's hitting the walls is only 1/4 as powerful as the light hitting the canopy. You doubled the distance, so the power was cut by 1/4. Now, when the light reflects back, it loses any even greater amount of power. In the same example., in order to get back to the center of the canopy, it has to travel 12" to the wall, then another 12" from the wall back to the center of the canopy. This means that it's traveled 24" instead of 6" like the direct light. At first most people think that this reflected light would be 1/4 as strong as the direct light, but becasue of the inverse square law, it's actually 1/8 as strong. Even that ratio is being VERY generous, because the light that's hitting the wall is scattering all around, and much of it doesn't bounce directly back to the canopy, but instead bounces 1, 2, 3, or who knows how many times more before hitting some green. Look on a photography website that deals with flashes in order to find out more about the Inverse Square Law.

I'm not saying that reflective material isn't important. i use it myself, but when you start talking about 70% effectiveness vs. 80% effectiveness of numbers like 1/8 or 1/16, you're splitting hairs and ease of use is probably just as if not more important.

white paint Mylar is a pain to keep clean.

I'd go with Exterior Flat White paint. It has a fungicide in it, so mold and fungus won't be a problem.

Mylar is deff. a pita, i would rather just use two coats of flat white it works well.

i also vote for white paint.

a. it looks cleaner
b. its easier to maintain/clean
c. easier to apply, imo.

mylar gets water spots on it if you mist the plants and loses it's reflectivity. It's a pain to keep clean.

white paint bro.

Flat white paint, mylar is nice and all but it's expensive and a total bitch to deal with.

My $.02, flat white paint, easy on, easy clean up, easy reapplication if necessary.
Mylar's more expensive, more difficult to keep clean, wrinkles and tears easily (which leads to hot spots on your plants and in your cab), not to mention a pain in the a*% to hang in a small, already assembled cabinet.

Good luck.

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Go with the mylar. Grow boxes, cabinets, and some of the cool grows around here would look even more bizarre to the cops and witnesses should they accidently become discovered. I think mylar adds shock value.

is it 100% required to have a reflective inner of a tote? I'm going to paint mine flat white, just wanted to know when its needed to budget my build. I have seedlings trying to break soil at my stage.

Quality Mylar is often multi ply, which helps enormously in terms of sealing light in and out. Space blankets are super cheap but the aluminum is not deposited very uniformly on them and they're easily damaged. I currently use space blanket material on the walls of my grow which are outside walls, because it was getting VERY cold in there. The blanket actually helped enormously, and I taped it down with foil tape, which has amazing glue on it.

My opinion: Mylar produces more precise reflections, and white paint makes much more diffuse reflections, but both are better than nothing. I suggest white paint and then a space blanket on top of that. It's pretty easy to do.

I'd go with the paint, and spend the mylar $ on the best bulb(s) you can find.

The reflectivity of the mylar, is based on a clean sheet, with no watermarks, no scratches, no folds or bends...

The paint will last virtually forever, whereas the mylar needs replacing often. Plus, the paint doesn't bend, tear, vibrate, scratch, fall on your lights/plants, nor does it capture moisture between wall and the plastic. (possible mold issues)

It's not like we use 100% of the light in the first place...so to me...there is no need to be anal about a couple of lumens. It just get's too expensive being a perfectionist when growing, lol.

ATM I'm strapped for cash so I've glued empty, and washed, chip packets to the inside of a PC case. (a fun way to get mylar)

Anyone think this will work?

Although I sometimes worry that with CFL's inside, the heat may transfer to the outside of the case and give the game away. I haven't started growing yet, just working out problems before they happen.