Perc

A perc (short for percolator) is a secondary water filtration component built into a water pipe. It breaks vapor into smaller bubbles, increasing surface area contact with water for enhanced cooling and smoother draws.

Key features:

• Creates additional filtration stages beyond the downstem
• Breaks vapor into smaller bubbles for more cooling
• Various designs: tree, showerhead, honeycomb, matrix, etc.
• Can be stacked (multiple percs in one piece)
• Adds slight draw resistance in exchange for smoothness

The physics is straightforward: smaller bubbles mean a larger surface area, which results in more contact with water, leading to better cooling and filtration. A single large bubble has less surface area relative to its volume than many small bubbles with the same total volume. Percs force vapor through small holes or slits, creating those tiny bubbles responsible for enhanced diffusion.

Design variations affect both performance and draw resistance. Tree percs use multiple arms with slits at the ends — more arms increase diffusion but also add draw resistance. Showerhead perc looks like a shower head with holes around the perimeter — a good balance of diffusion and airflow. A honeycomb perc is a flat disc with many small holes, offering excellent diffusion with relatively low drag. Matrix percs combine vertical and horizontal slits for multidirectional bubble creation.

Multiple percs increase filtration but also increase drag (the resistance you feel when inhaling). Some people prefer single percs for easier draws. Others want maximum filtration and are willing to accept the additional resistance. It's a personal preference balanced against the type of sessions you prefer.

Percs in your setup: Percs are built into the water pipe during creation — you can't add them to existing pieces (though you can buy ash catchers with percs that attach between your bowl and downstem). Water level matters with perc chambers — each chamber needs enough water to function, but not so much that it restricts airflow or causes splashback. Most pieces have waterline indicators, or you can test by taking a practice draw without any material. Clean percs regularly since resin builds up in the small holes and slits, reducing their effectiveness. Isopropyl alcohol and coarse salt work well — shake the solution through the piece to scrub the perc surfaces.