Re: New to hookah. Possible Problems?
purging is when you blow air from your lungs back through the hose into the hookah. your hookah (most likely) has a small "stem" with a screw-on cap, near the hose port with a ball bearing resting inside (purge valve). when you blow, the ball bearing will lift up and allow you to clear air and smoke from the base. if you blow way too hard (or if your purge valve gets stuck closed), you can actually force water back up the main stem, creating a horrible volcano.
with the foil, practice makes perfect. set the bowl upright on a sturdy, flat surface and use both hands to evenly smooth the foil over the lip of the bowl, pulling down around the edges and pressing the foil onto the outside of the bowl. i like to use a big enough piece of foil that i have at least 2" off each side of the bowl. use just enough pressure to get a tight seal, but not so much that your foil rips. then take either your palm or a couple fingers and run it around the rim of the bowl, pressing hard to make a nice smooth seal. also, try using either 2 layers of regular foil or a good heavy duty foil. while we're at it, never use "non-stick" foil; it has chemicals not good for smoking. if you're still uncertain after a couple tries, watch one of the many videos that members have made about packing a bowl.
if you don't have a grommet, definitely get one. they're cheap, easy to use, and last a long time. in a pinch, you can use several layers of foil wrapped slightly loose around the cone at the top of the hookah so that when you press the bowl on the foil will compress and give you a workable seal, but this is much more work and not guaranteed to give you as good a seal as a well fitted grommet.