haha therw has been this exact thread like 5 times in the past 6 months or soo. Night wolf got it but left out the part of filtration so I ll try to elaborate. bong consists of a chamger (tube) which you fill with water and a steam connected to a bowl dips in in this chamber where as the steamis under water quite a bit. When you pull or suck the air out of the main chamber with the water vacume occurs and pulls the smoke down the steam through the water and up the chamber to your mouth. what this does is cool and filter toxins from the smoke. This is very basic I recomend Glass on glass bongs with a pull carb, and multiple difusers or percolators, all of this improves your smoking experiance.imp: