Percolators and Diffusers

Percolators & Diffusers


To Percolate:

(of a liquid or gas) filter gradually through a porous surface or substance.


To Diffuse:

become or cause (a fluid, gas, individual atom, etc.) to become intermingled with a substance by movement, typically in a specified direction or at specified speed.

What Are Percolators and Diffusers and How Do They Work?

The water inside bongs cools the smoke as it travels from the ember to your mouth.  The smoke is forced into air bubbles as it is surrounded by water and passes through the bong, lowering the surface temperature of the smoke before it reaches your lungs.  This process allows for cooler smoke and larger hits, but what if the smoke could be cooled down even more?  Could the user potentially take even larger hits?

Percolator and Diffuser bongs are simple in concept, and the two names are essentially, interchangeable.  They both force the trapped air bubbles of smoke to break up into many smaller smoke bubbles, increasing the surface area that the water can travel along and maximizing the cooling effect.  Imagine one large smoke bubble, travelling from the ember in your bowl, down the stem, into the water, up the tube, and into your mouth.  The water that is cooling the smoke cannot penetrate the air bubble, so its cooling effects are limited to the surface of the smoke bubble only.

Theoretically, the inside of the smoke bubble has not been cooled by the water and is now much hotter than its surface.  While this method has worked for decades and is still much cooler and smoother than simply smoking a joint or a pipe, the percolator bong revolution took over about a decade ago and hasn’t looked back.

Nearly every single bong that we sell on is some form of percolator or diffuser bong.  Just imagine: What was once one smoke bubble, travelling from ember to your mouth, and only being cooled by the water on its surface, is now hundreds, if not thousands of smoke bubbles, with a hundred times more surface area for the water to encapsulate and cool.

Percolators and Diffusers come in a variety of different shapes, sizes and forms.  New styles are being invented on a regular basis and classic styles are constantly being refined and evolved.  While there are too many styles to name completely, we have chosen the most commonly used styles as well as styles found in our store.

Types of Percolators and Diffusers


Frit Percolator

The frit percolator is arguably the most effective of all percolators.  By combining hundreds, if not thousands, of tiny pieces of crushed glass together and melting them into a porous mass, microscopic openings are created through which smoke and water can be filtered.  While this is arguably the best percolation system out there, one draw back is that it can quickly clog up due to the tiny sizes of the holes.  Frit Glass can be shaped many different ways, but the exterior always looks the same.  Depending on the colour, it can look a lot like rock candy or even small seeds.

Atomic Percolator

An Atomic Percolator is a round cylinder with slits around its perimeter. The smoke and water flow into the cylinder and are forced out through the many slits.

Respirator Percolator

A Respirator Percolator resembles just that: a respirator. Essentially, it is four circle percolators flipped on their side and combined in twos on either side of the entry chamber. The smoke and water travel down the tube and are forced out through the four individual circle percolators. Four circle percolators ensure a smooth and cool draw. This respirator percolator is part of an ash-catcher for a bong.

Tree Percolator

A tree percolator incorporates any number of thin tubes with holes at the bottom into a circular dome, which resembles low-hanging branches dangling from a tree.  The arms are connected to the bong through a stem, which draws the smoke up and into the tree percolator.  The holes or slits at the bottom of each arm are submerged in water and the smoke is forced through them, cooling it on its way to your mouth.

Triangle Percolator

A Triangle Percolator is a three-dimensional pyramid with horizontal slits around its three edges. The smoke is forced up through a central chamber and into the pyramid. Similar to the cube and domed percolators, the smoke and water are smashed against the top before falling back down and being sucked out of the slits at the base of the pyramid. The smoke cools significantly as it moves up towards the user’s mouth.

Cube Percolator

A Cube Percolator is similar to a Domed Percolator in as much as it flows up through a tube and smashes against the top of an enclosure. However, with the Cube Percolator, the smoke and water fall back down into a cubed chamber where they are then forced out through a number of fine slits around the edges of the cube. Not only does this ensure a great bubbling show, but significantly cools the smoke before reaching your mouth.

Diffuser Downstem

A typical downstem has one hole at the bottom of a long tube.  This allows the smoke to be pulled from the bowl, down into the water inside the bong.  A downstem diffuser simply means that extra perpendicular holes or slits have been added to the bottom of the tube.  This enables the one, large smoke bubble to be broken up into many smaller bubbles, increasing the surface area that can be cooled by the water.  These are an efficient and economical way to turn a simple bong into a diffuser bong.

Showerhead Diffuser Downstem

A showerhead diffuser is similar to the diffuser downstem, except that it has a much more intricate diffusion design.  While the diffuser downstem incorporates multiple, perpendicular holes or slits into the bottom of the tube, the showerhead diffuser pushes the base out into a bulb, and adds parallel slits.  By making them parallel over a protruding bulb, more slits can be added than with the typical diffuser downstem.  This makes for much more visible and tangible diffusion.

Disc Percolator

The Disc Percolator is quite straight forward, but it can be customized quite extensively.  Essentially, it is a solid, glass disc inside a bong, with the same circumference as the bong.  It acts as a screen which breaks up the large smoke bubble into hundreds of tiny ones, increasing the surface area that the water is able to cool.

Turbine Diffuser

The Turbine Disc Diffuser is a variation of the Disc Perc. Not only does the turbine break up the large smoke bubble into a multitude of smaller ones, it also spins the water and smoke to create a turbine effect which helps cool the smoke even more.  The centrifugal action of the turbine pushes the smoke and water out to the sides of the bong and hopefully, away from your mouth.  It is a percolator/diffuser as well as a splashguard.

Upline (Ladder Percolator)

GRAV’s Upline incorporates a Ladder Percolator in its design.  Essentially, it is multiple cylindrical chambers stacked on top of one another.  While each chamber is as wide as the bong itself, they are interconnected by much smaller tubes, which both the smoke and the water are forced through.  Each time the smoke enters a new chamber, the water bashes it around before it’s sucked up into the chamber above.  Depending on the height of the bong, there can be anywhere from 3 to 7 chambers of the ladder percolator.

Shower Head Percolator

A Showerhead Percolator forces the water and smoke up through a small tube and into a bulbous head, lines with vertical slits around its perimeter. The water and smoke spin in a centrifugal motion before being pushed out of the slits and travelling up the bong. This action splits up the larger smoke bubbles into a multitude of tiny bubbles, maximizing the surface area that the water can cool.

Sprocket Percolator

A Sprocket Percolator resembles a Disc Percolator in as much as it is a flat, glass screen, which is the same circumference as the bong tube.  However, instead of multiple holes punched through the disc to allow air and water to flow through, the Sprocket Perc has multiple slits all around the edge of the disc, while the centre is solid glass.  The Sprocket Perc is a variation of the Disc Perc.

Umbrella Percolator

The Umbrella Percolator is a simple yet effective method of splitting up your smoke bubbles in to a plethora of smaller bubbles. Umbrella Percolators are usually found in smaller rigs because of their small size and simplicity. Essentially, the Umbrella Percolator is a small chamber with vertical slits. The smoke and water flow into the chamber from above and are forced out through a small number of slits at the base.

Coil Recycler

A Coil Recycler is very similar to a recycler diffuser except for an additional coil. The coil dramatically extends the distance that the cooled smoke has to travel from the recycler and in this process, cools down the smoke significantly. Combined with the recycler diffuser system, they ensure a smooth delivery to the user.


Recyclers are more diffusers than they are percolators, although the difference between the two terms is negligible.  While Recyclers don’t necessarily use a percolation system, they diffuse the smoke by spinning it around in an upper chamber while also allowing a significant amount of it to be re-sucked down into the water through a secondary tube.   This recycling action ensures that the smoke has been at least spun around in a turbine, if not re-cooled through the water again, multiple times.

Splash Guard

A splashguard is usually found in the more intricate percolator and diffuser bongs and rigs. They are always placed near the top of the bong/rig and as close to the mouthpiece as possible. Quite simply, all a splashguard does is try to block the mass of bubbles and splashing water that is taking place below in your percolator, from reaching your mouth. When you “kiss the fish”, you suck up a bunch of unwanted bong water, and this can really kill a vibe or ruin your hit. The splashguard does all it can to stop that from happening. They’re not perfect, but they are indispensable.

Inline Percolator

An inline percolator is a long, horizontal glass tube with multiple holes or slits cut out of it, submerged in water.  The smoke from the bowl is pulled through the horizontal tube and forced out through its many slits, breaking up the smoke into a multitude of smaller bubbles, maximizing the cooling efficiency.

Honeycomb Percolator

The Honeycomb Percolator is the most common variation of the disc perc.  It is essentially a Disc Perc punctured with as many holes as possible, forming a honeycomb pattern.  The water sits right below the disc until the user pulls smoke through the bong.  The smoke and water are forced upwards through as many as 50 different holes and in the process, are broken up into many smaller bubbles, cooling the smoke significantly.

Organ Percolator

An Organ Percolator is similar to an upside down tree percolator, except it has no slits at the top of the tubes.  It closely resembles a church organ, hence the name “Organ” Percolator, and provides quite a show of bubbles while in use.  Because of the lack of slits and holes on the side of the arms, it is a quite easy bong to clean.

Circle Percolator

A Circle Perc closely resembles the Showerhead Diffuser, except that it is a standalone-submerged percolator, which is usually embedded within the middle of a bong.  Smoke is pulled up through the dome and then forced back down, out of the submerged slits and up into the user’s mouth.  Just like the Showerhead Diffuser, the slits are parallel and cut into a circular disc.


GRAV are perhaps best known for their range of Helix Glass products, which feature minuscule, angular Tungsten holes poked into the sides of the upper tube.  This feature utilizes Swiss mathematician and physicist Daniel Bernoulli’s principle of airflow, first published in 1738 in his book Hydrodynamica.

It states that an increase in the speed of a fluid occurs simultaneously with a decrease in the pressure exerted by the fluid.  This means that a rise in pressure in a flowing fluid must always be accompanied by a decrease in the speed, and vice-versa.

When applied to their glass products, the Tungsten holes produce something called the Venturi Effect, which is the reduction in fluid pressure that results when a fluid flows through a constricted section of piping.  This process contributes greatly to the cooling and slowing-down of the airflow.

Grid Percolator

A Grid Percolator is similar to a Disc Percolator except that it has an interior chamber.  While the disc perc is simply a glass disc separating the water and air inside the bong, incorporating some type of percolator or diffusor, a Grid Perc is more like a three dimensional disc, which allows the smoke and water to pass inside of it and then out through a multitude of perpendicular slits.  Some Grid Percs can have multiple layers within, which the water and smoke must be forced through.