Hi Nidaleeee,
haven't heard of pertile, do you mean perlite?
if so , Perlite is very light and is brilliant for lightening soil and improving drainage. something heavy like marbles (do you have access to a lot of marbles by any chance?)
or pebbles will reduce the amount of water your soil can hold, but wont really help drainage as well as perlite which has uneven surfaces and allows for better air retention as well as fluid drainage. if you cant get or don't want to use perlite you would be better off with horticultural grit, but it (like marbles and pebbles) will increase the weight of your mix-not great if you have big pots and need to move them.