hello all
new here, but old time indoor/outdoor gardener
I have 2 growrooms and use HID lights
I use mylar on the walls and paint the floors flat white.
mylar reflects 95% heat and light evenly, next best thing you can use is a white flat latex paint.
the beef I have with mylar is that it is hard to work with and tears real easy...if I could afford it I would use foylon 99% light reflected thicker material , easy to clean and reusable for years!
some will say use aluminum foil...the problem with foil is that heat spots are created and it does not reflects the light evenly...
just my 2 cents
Dan