Percolator bongs and water pipes look amazing, but their true awesomeness is in their function: The first purpose of a water pipe is to filter and cool smoke before inhalation. (Here at your favorite online headshop, we love our hand pipes. But we all know there's a significant difference in the smoothness of a hit between a standard water pipe and a dry hand pipe.)
A percolator bong (also known as a "perc") takes filtration a step further to create the smoothest hits of all. They work by forming tiny bubbles as the smoke passes through, which gives the water more surface area to interact with the smoke.
Water is a polar molecule, so it will attract to other polar contaminants found in the smoke and filter them away from the substance you’re ultimately trying to inhale. The more surface area the water has to interact with the smoke, the more it will filter out all of junk and leave you with the smoothest vapor for inhaling.
Downstems with slits in the bottom were the original percolators, and designs have kept evolving since. Tree percs function like a dozen downstems in one, giving more filtration the more arms it has. Showerhead percs also function on the multiple slit model. Other percolators, like the honeycomb, use tiny holes instead of slits to filter the smoke.
While percolators may seem complicated, they are all designed to provide the user with extra filtration. Some have more parts than others, but choosing the best perc is all dependent on user preference.
Keep in mind, tiny holes can increase the drag, but more holes will both decrease the drag and filter even more. You can also add perc attachments to your water pipe for maximum filtration, but more percs can also lead to increased drag.
The best way to figure out which perc is right for you is to experiment with different kinds and get a feel for the different levels of filtration and drag.
Remember, kids: There is no such thing as too much filtration!