i use sunshine #4 witch is a soilless mix made up of perlite moss vermaculite and i also like to add 1cup of crushed lava rock per two gallons of the soilless mix. this is basically low tech hydro and i get the same results as more complex hydro set ups. just remember if you go this route buy a good ph meter and keep the ph at 6.3 and they will grow grow grow!!!!!!!!!