with my vapir no 2 i took out all the vapir screens and fill the brass bowl up with about a spliffs worth of stuff... it's quite expensive to run. But i like this vaporizer. once the bowl is full i gently place a big steel screen on top of it cheap from my local head shop... then screw on the top which has empty filter holder. Chuck on the tube and i'm good to go! if the bowl wasn't brass i'd rate it more highly.