Using a glass on glass bong is simple. Smoker inhales with his or her mouth sealed over an opening at the top. This reduces the air pressure in the chamber of the bong above the water level in the bottom of the bong. To equalize the pressure, the atmosphere pushes air through the combustible matter releasing smoke in the bowl travelling down the stem. The smoke then bubbles through the water into the chamber and into the users mouth and lungs.
Know the parts of an average bong.
Fill the Water Pipe With Water
In order to use your hookah, bong, or water pipe, you must first fill it with water. Using tap or bottled water, fill the central cavity of the water pipe until the water covers the downstem.
To test that you have added the correct amount of water, suck on the mouthpiece of the water pipe. The water should bubble, but it should not come through the pipe into your mouth. If it doesn't bubble, add more water, and if it comes into your mouth, pour out some of the water.
Add the Tobacco or Shisha to the Bowl
Take some tobacco out of your tobacco pouch, and add it to the bowl of the water pipe. If you are using a classic hookah style pipe, they often feature relatively large holes in the clay bowl, and you may need to add a charcoal screen over those holes. A charcoal screen or filter is simply a small metal filter that sits on top of the clay bowl, and in a pinch, you can even make your own out of a bit of window screen.
If you are using a bong-style water pipe, the bowls are usually small enough to hold pipe tobacco, flavored shisha, or any crumbled-up smokeable buds without the addition of a filter. If the water pipe is used, be sure to clean any ash or residue out of the bowl before packing it with smokeable leaves.
Add ice to your bong (optional).
Ice will cool down the smoke, which some people believe makes it easier to inhale. Carefully put some in the water to cool it down, removing the downstem first so that the ice doesn't break it on the way down.
To smoke using a water pipe, place the mouthpiece by your lips and draw in. Watch as the smoke draws down from the bowl, through the water, and into the chamber.
When the chamber is full of smoke, release the carb if your water pipe has one, and quickly inhale all of the smoke. If you cannot "clear" all of the smoke out of the water pipe, hand it to a friend. They can inhale the smoke without even relighting the material in the bowl.
If you are using a classic hookah, simply hold the mouthpiece to your mouth and draw the smoke into the water until it begins to bubble. Remove the air valve as needed when the central chamber gets full of smoke.
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