How to Choose a Downstem
The downstem is the piece that enters the water in a water-pipe. It is an essential part of the device; without it, we wouldn’t have a functioning piece of glass. The purpose of a water pipe is to filter and cool the smoke before it reaches your lungs. Downstems do just that; they provide the cooling necessary while also adjusting how smooth of a draw you will take. The smoothness of the bubbles, or percolation, can be changed by swapping the downstem and can dramatically increase the overall experience of smoking. The Showerhead Downstem from PURR has a great diffuser at the base of the glass. Some water-pipes offer “stem-less” options, which are nice because you don’t have to worry about changing a downstem, but that can be a downside as well. Some may even prefer two or more down-stems, one for concentrate, one for blends, or even for the convenience of just having a clean one handy while you clean the other. Read below for measuring tips, as well as information on styles and designs.
Types of Downstems
As far as styling and design go, there are three main things to consider: size of glass joint, thickness of air pathway, and percolation. These three things determine how the piece will function, and also, whether your new downstem will fit your water-pipe. A larger joint size will allow better overall airflow, but can also extend your bowl-piece away from your pipe, which may look funny on some smaller water-pipes. The air pathway can be tapered down to a thinner size to also help with keeping smoke dense and cloudy. The thinner pathway allows for smoke to not mix with too much air and results in slightly thicker clouds. Also, there will be less glass surface area for your vapor to condense on, making it harder for your vapor to stick to the glass before it hits your lungs. This is the same reason many rigs designed for concentrates are being made smaller; some even have 10mm joints that can fit in your pocket. Less glass means less glass available for the vapor to stick to, and results in a slightly stronger hit. The percolation of a downstem depends on the air holes or slits at the bottom. While some may only have a couple of small holes, which is better for conserving concentrate flavors, some are beasts that can produce fat bubbles that stack on top of each other for superior percolation and filtration. Common types of downstem percs are slitted, multihole styles, and showerheads. They all work somewhat differently, but their functions are the same. The basic consensus is fewer holes for concentrates, and more for blends.
Measurement is key when choosing a new downstem, and many retailers measure differently. Here at Kannakart, we measure the length of the downstem as follows; from the top of the ground glass joint that goes into the pipe, down to the tip that goes into your pipe. The size of the joint depends on what you want or already have. If you have a collection of 14mm bowls, you should probably stick to a 14 mm female opening. If your bong or dab rig has an 18mm opening (also referred to as 19mm), you’ll want an 18mm male glass joint on your downstem. We have many adaptors if you want to fit different downstems and ashcatchers together that are not the same size. On downstems with an extended glass joint that may stick out, you will still measure from the top of the glass joint that goes into the water pipe, not the side you put your bowl piece into. If you’re unsure about 14mm or 18mm and have no way to measure precisely, you can refer to the literal “rule of thumb.” The average size of the tip of your thumb will snugly fit into an 18/19mm opening, while your pinky will snugly fit into a 14mm opening. If you’re still having trouble, 18mm is between the size of a dime and a penny, and 14mm will be much smaller than the dime.
With these measuring tips and style suggestions, you should be able to buy with confidence. Remember, since these parts are removable; they can break, so be careful! Lastly, remember to size your stem appropriately and choose something that’s right for your method of smoking, and you’ll be more than satisfied with your decision. Happy smoking!