I know "The Cannabis Grow Bible" could be wrong... However, it is well written and the author - Greg Grreen did a great job writing it. This is what he wrote: " White-colored material is best for reflecting light; not shiney, glossy white, just pain matte white. A white wall will relect more ligt than a mirror or foil - if you use foil, use the dull side. A cheap can of lflat white paint will give you almost 99% reflectivity for a couple of years. Others line their grow areas wih Mylar..."

At one point I tried putting the packing peanuts styrofoam in the buckets, but found after about 10 days a yellowish film started on top of the soil. I took it all out and put it on the floor which is working very well that way.