you CAN use an inch of sand at the top of the bucket for past control..
but it is heavy and stifling.. not really good in your soil..
try promix (or any other non-soil substrate) and cut with perlite..
you will love the results..
or just use Miracle Gro.. that works fine too.. just add you guessed it.. perlite!
lol

~MG a.k.a. le Maine développé