Perlite question

This is my first indoor grow..400w in a grow hut...am i supposed to layer the perlite in the bottom first,or does it get mixed in the soil?

perlite breaks up dense soils when mixed in, a soil with perlite mixed will drain faster and dry out faster than without perlite

We started out adding a layer of perlite on the bottom of our flowering pots for drainage and to help keep the roots from bunching up. It turned out that when the roots reached the perlite at the bottom, they'd pretty much stop growing. We ended up having more room for root growth without the perlite layer. Aside from that, Shonts is correct that about 20-25% of the soil is often perlite.

Cool..thanks for the replies.Hope to post some pics of my grow soon.