The problem with mirrors is that they will absorb HEAT.

After 10 hours under a 600W HPS, those slabs of glass will be HOT.

Mylar is the best.

Aluminum foil... if you're using that, I think it's better to use flat white paint.
turtle420 Reviewed by turtle420 on . foiling hey i m only using aluminum foil and im still losing way too much light if theres 600 ws in the room its probably recieving 400ws. i wanna get somthin thats pretty much a mirrior but i dont wanna spend that much money i saw one person like burtonukk7 has it in his closet where its like mirrios what is that stuff how much does it run were do you get it Rating: 5