Mylar over Soil

So my friend is doing a custom medical grow with CFLs... Mylar was used over the top of the soil and there is a great increase in light penetrating from the bottom up, it's very obvious! The mylar was from the emergency blanket type, so it's light. It's sort of floating on top a bit so air still gets around / under it fairly well. Any opinions on this? Anyone else try this? Seems like a very cheap and easy way to direct wasted light back to the plant. If you are curious just cut some yourself to see the difference, it's pretty substantial.

put it on walls i dont see the point putting it on soil its kinda useless i add alote of perlite on top soil it reflects light and keeps mold away

peece

Yes no need for mylar on soil. It might hinder normal respiration process anyway.

Okay. Like I said there was a noticeable difference, huge difference really. Maybe just perlite is a better way to go.

Like others said, I feel like it's just a way to cause yourself more problems (mold...). I would put some mylar around the edge of the pot so it acts as a reflector, just dont cover up the soil.... now if you were doing hydro it would make perfect sense to do this on top of your res/bucket.