Bongs offer health benefits as bong water tends to remove a number of carcinogens, lowering the smoker's chances of contracting illnesses such as lung cancer. For marijuana users, the bong offers a better high than most other methods (except for oral administration), as the smoke is less harsh, and quite cool (even more so when mixed with ice), enabling the inhalation of more smoke.
With marijuana use, bong water can be saved, and after being stored for a period of time, a slimy resin can be collected from the bottom of the container and smoked. However, drinking of bong water is not advised, as it contains negligible amounts of THC and higher levels of carcinogenic material
A bong can be made of any material which is impermeable to both air and water. Glass is often considered the best material for fabrication of bongs, because it is easy to clean, durable, and absolutely air and watertight. Plastic is also a popular, but is generally used for bongs which will not be used for a long time, as they tend to develop problems with the seals around the stem and conepiece as they are generally not made with as much care as a glass bong. Other popular materials include ceramic, wood and metal.
The most basic bong consists of a mouthpiece, chamber, stem and bowl (aka conepiece, dooey, etc). The bowl is almost always made of metal, as it must be heat resistant in order to allow the substance to b smoked to burn, although one will often find that the bong is moulded in a single piece made entirely of the same material. Bongs often have a hole on the side (called a "carb" or, in Australia, a "shotgun hole") to allow air to bypass the stem and allow large amounts of smoke to enter the user's lungs rapidly.
Bongs can, however, be very elegant in both functional and non-functional ways. Functional ways include addition of extra chambers (which allows further cooling of the smoke), multiple bowls (for longer, bigger hits) and multiple mouthpieces (so more than one person can smoke at once).
Various bong designs include:
Standard Bong - a simple bong made of a plastic bottle with a piece of rubber garden hose place approximately 1/3 of the way up. In this budget design, the bowl is generally made from a beverage can made into the shape of a cone. The materials can vary, but this is the basis of most bongs in existence.
Gravity Bong - Unlike its name suggests, this bong has absolutely nothing to do with gravity. This type of bong is generally made from a plastic milk bottle (because it has a nice handle) and a bucket. A hole is put in the milk bottle cap and a bowl placed in this hole and sealed there. The bottle is then cut off the bottle and placed in the water filled bucket. One places their herb of choice in the bowl, places the cap back on the bottle and pulls it out of the water while lighting. Because of the way in which this bong functions, it would more appropriately be called a suction of vacuum bong.
Hookah - A variation of the standard bong in which the smoke is not inhaled through the bottle's mouth, but through a plastic tube. This allows the user to layback while smoking and creates a more relaxed smoking environment. Commonly, a hookah will have the stem vertical and the bowl on the top of the chamber.
Double Chamber Bong - Another variation of the standard bong in which a second chamber is added for extra cooling effects. In this design, after bubbling through the water initially, the smoke enters a tube leading to a second chamber (always below the waterline) which causes the smoke to bubble through water a second time (further cooling it). The smoke is then inhaled by the user. This design can be expanded to include as many chambers as the maker wees fit. In this design, if a carb is present, it should always be on the last chamber through which the smoke passes.
The Group Bong - This is often among the most elaborate bongs made. In this design, multiple mouthpieces are attached to a central chamber, allowing multiple users to smoke at the same time. There are an almoqt infinite number of variations to this type of bong, but they can be classified into 2 distinct groups, Individual Bowl or Group Bowl. In bongs of this type which are classified in the Individual Bowl category have 1 bowl for each of the users. In Group Bowl bongs, there is 1 large bowl for all the users. These bongs are almost always very large and often consist of multiple chambers. Many commercial bongs of this type even make use of pumps to maintain a constant vaccum in the chamber(s) which allows the users to directly inhale the smoke, because "clearing" the chamber of these bongs would often take hours, even with multiple users.
"If anyone wants to come for at hit, I just got a new bong that 6 people can smoke at the same time!"