I have one that tons of people will shit all over probably.
Myth: Mylar is superior to flat white paint
Fact: Flat white Paint is superior to mylar except under optimal conditions, and even still it has so many drawbacks it fails to be worth the tiny tiny tiny reflective gain over paint.
Unless you pull mylar perfectly tight so it's not all wrinkled it isn't even better brand new and perfectly clean.
Then part of the problem with mylar is that is gets so dirty so quick and easy and is difficult to clean up to say the least so many don't keep it clean often enough to truly keep it better than paint.
Because mylar provides a space for critters to breed and hide from your sprays, it's not worth it.
Because mylar blocks airflow it can trap moisture between itself and the walls of your grow. It can actually encourage mold issues because of that and the fact you aren't getting behind it to clean and disinfect as often as you should.
With paint, it's very easy to slap on a fresh coat at any time, between every couple grows or whenever needed, and that fresh coat is a great way to not only keep your grow as EVENLY reflective as possible but seal in any spores, fungus, mold, whatever that might have escaped your cleaning. It is easier to repaint than it is to disinfect and clean a room with mylar by a large margin.
White paint can never hotspot, period. Your growth will be more even in the room provided your lights are arranged well.
The ideal paint (or at least one of them) is Behr Ultra Pure White flat wall paint. Never use a gloss, and be careful of anything other than a paint made to be this pure white. Paints that aren't perfectly pure white will not reflect the spectrums of light you are using properly, and could turn usable light into unusable light just by skewing the color even the slightest amount.
If you have proven something wrong that you have heard many times through out books or other growers please list them here i am very interested to now and i'm sure others would to
