Percolators and Advanced Filtration in Waterpipes

Percolators and Advanced Filtration in Waterpipes

Percolation is a topic that comes up more and more as scientific glass becomes increasingly prevalent in the smoking community. Over the past few years, there has been a sharp increase in the number of companies categorizing themselves as “scientific glass” companies. Traditionally, these companies fall into this category based on two characteristics: the type of glass used, and the use of advanced filtration, mainly with percolators.

Most commonly a company claiming to be scientific will use a form of clear glass, sometimes featuring a small amount of colored glass in special cases. The clear glass is most likely either borosilicate (such as Medicali) or German shot glass (such as Roor). These are both highly notable forms of glass commonly used by scientific glass companies. Although these glass types are common in the scientific glass community, the glass Is not the only thing that puts these companies in the scientific category. The second characteristic that classifies these companies as scientific is the presence of percolators found in most, to all of their glass pieces.

What is a Percolator and What Does a Percolator Do?

Percolators are essential to the method of cooling smoke developed by scientific glass companies to provide a more flavorful, smoother smoking experience. Classically, a percolator breaks the smoke into smaller sections in order to allow it to cool faster, however now a percolator can be considered to be any method of cooling or smoothing out a hit. The most common form of percolation found in any waterpipe is a diffused downstem. This is just a simple tube that extends down from the bowl piece that first introduces the smoke into the water. A diffused downstem will have some type of small slits or series of holes to break the smoke into smaller particles, however, some companies do not consider this to technically be a percolator.

Tree Percolators

One of the most classic examples of a percolator (or perc for short) is a design called a tree perc. This perc involves water filtration and is essentially one main tube that pulls air up from the chamber below it, then brings it back down through a series of usually anywhere from 4-64 smaller slotted tubes. These smaller tubes then disperse the smoke in the form of small bubbles into an upper smaller chamber filled with water, thus allowing the water to more quickly cool the smaller particles of smoke. The tree perc gets its name due to the resemblance it shares with a weeping willow tree due to the large “trunk” and low hanging “branches.”

Showerhead Percolators

Another common percolator is called the showerhead perc. Functioning very similar to a tree perc the shower head is essentially a tube that pulls the smoke upwards to a new chamber then down and out into that new chamber via a series of small slots that break the smoke into smaller particles to be cooled more quickly by the water inside of the chamber housing the perc. The main difference between a showerhead and a tree perc is the number of slits, the orientation of the slits, and durability of the perc. A showerhead perc will always have vertical slits along the bottom of the perc, whereas tree percs have horizontal slits along the bottom of their “branches”. Showerhead percs are also considered to be slightly more durable as their bell-shaped design increases the rigidity of the glass when blown correctly. Despite these small differences, many smokers consider the two to be fairly similar as far as cooling methods go and tend to pick a favorite based on aesthetic.

Inline Percolators

Inline percolators are another common percolator seen in many scientific glass pieces. This perc is different from the other two previously discussed (tree and shower head) due to the fact that it is most commonly attached to a fixed downstem in the bottom chamber of a water pipe. Much like the other two, it works by breaking the smoke into smaller particles to be more quickly cooled by the water in that chamber. Unlike the other two, however, it does not stand vertically. An inline is a straight horizontal tube with parallel slits along the bottom.

With these three types of percolators, the basic rule of thumb will be the more slits and the more bubbles produced, the smoother the hit. Higher-end companies that use these methods of percolation also prefer to polish the slits in their percs (percolators) in order to allow bubbles to escape in higher numbers causing a higher level of percolation.

Honeycomb Percolators

The search for the method of percolation which causes the most bubbles lead scientific glass companies to search for new percs that created increasingly smaller and more numerous bubbles. This lead to the invention of the honeycomb and frit disc percs. Honeycomb percs, as the name suggests, bear a striking resemblance to a piece of honeycomb. They are usually round discs located toward the bottom of a water pipe covered entirely with tiny holes, water is put into the water pipe until the water level is flush with the bottom of the honeycomb disc. This causes the perc to draw the water and smoke upward when inhaling while breaking it into extremely small and rapidly dispersed bubbles. Some companies have even begun stacking multiple honeycombs very close together, in order to promote more percolation. This can be seen commonly in companies such as diamond glass.

Frit Disc Percolators

Frit disk percs are very similar and somewhat resemble a small disk positioned in the same manner as a honeycomb perc. The disk upon closer inspection has an appearance something like tiny rocks compacted together, which is actually a glass or ceramic material (sometimes substituted for glass) called frit. Upon first glance it appears that the disc is a solid object, however, upon closer inspection, it becomes clear that between the frit is a series of extremely small crisscrossing tunnels. This produces a similar effect to a honeycomb perc, except with much smaller and more numerous bubbles. Many smokers believe that these two percolators (honeycomb and frit disk) have the highest ability to cool smoke, however, they both share the downside of being extremely difficult to clean entirely. This causes many smokers to avoid these percs, however, there are cleaning solutions, like Grunge OffFormula 710, Formula 420, or others, which should get them nice and clean after a long soak.

Concentrates and Advanced Filtration

Some companies have chosen to continue down the road of finding new methods of percolation that work in similar ways (breaking the smoke into smaller bubbles), but don’t fall into the classic designs of the five aforementioned percolators. This can be seen in companies such as Sky, Sovereignty, and Hisi. Other companies decided to go in a different direction and search for new methods of percolation that aren't designed around breaking the smoke into smaller particles through the use of bubbles. This is due to the rise in public interest of concentrates.

Early in the massive expansion in the popularity of concentrates, enthusiasts discovered that the more percolation, in the form of bubbles, vapor filters through the weaker the flavor becomes. This brought up an interesting conflict in the concentrates community between having a more flavorful hit and having a smoother hit. In order to achieve the best of both worlds, some companies began searching for alternatives, and a few favorites soon began to rise.


The most popular in the modern concentrate community soon became a method of percolation referred to as a recycler. This method of percolation works by essentially pulling the smoke in a continuous loop, up, around, down, and back up a water pipe through a series of carefully and meticulously crafted tubes. This is done in order to preserve the flavor of the hit as much as possible while simultaneously providing the smoothest hit possible. The reduced amount of bubbles is what allows the flavor of the concentrate to remain intact through this high level of percolation.


Another company that has become popular in the concentrate industry is Grav Labs. This is due to them owning a company called Helix who many concentrate vapers turned to in their search for a percolator involving fewer bubbles. Helix specializes in a type of percolator the essentially infuses cool air from outside of the glass piece into the smoke or vapor. This is achieved by three to four very carefully placed and meticulously angled air intakes that create a tornado-like effect, rapidly cooling the smoke. The effectiveness of this perc not only allows for a flavorful and smooth hit, but also an aesthetically pleasing hit. This has led the company's Helix to be one of the preferred technologies in the industry for both dry herb and concentrate smokers.

Percolation has surely played a big role in the way people buy, maintain, and create waterpipes. This has lead to a wide range of options for the consumer that seems to be ever expanding. There are far more percolators than have been explained in this article due to this rapidly expanding market, but we have decided to stick to the most common to provide a simple view of what has evolved into a very complex market. Ultimately, this blog post should serve as a good guide to understanding how percolators work, the differences between them, and some of the new developments currently shaping the market.

*These statements have not been evaluated by the United States Food and Drug Administration.

**The beliefs and opinions expressed in this blog are not those of Waterbeds ‘n’ Stuff.