How to measure the water level and temperature in a glass bong for optimal filtration and cooling?

If you are a fan of smoking herbs or tobacco with a glass bong, you might wonder how to get the best experience possible. One of the factors that can affect your enjoyment is the water level and temperature in your bong. In this blog post, we will explain why these two aspects are important and how to measure them correctly.

Why does water level matter?

The water level in your bong plays a significant role regarding filtration, temperature, and hit. Getting the optimal water level means getting the most of your bong. The water level affects how much smoke is filtered and cooled by the water, as well as how easy or hard it is to pull the smoke through the bong.

There are three types of water levels and their effects on how your bong functions:

  • Overfilling

    : The water level goes over the downstem almost up to the neck. This is good for those who are after huge amounts of filtration. The great amount of water lowers smoke temperature, giving you a hit that is cool and smooth to the throat and lungs. Downside is that you have to put much effort to pull in the smoke. There’s also a greater chance of you getting bong water in each pull.

  • Underfilling

    : The water level barely covers the slits or gills of the downstem. What this does is that you get more flavor with each drag. Reason is, there is not enough water to filter the smoke going through the stem. Others say this negates the use of the bong since you’re just getting smoke like you would a pipe. This leads to low filtration, which can increase the chance of irritation in your throat and lungs.

  • Optimal

    : The gills or slits are covered just right. You get to enjoy both filtration and flavor. You enjoy the taste of your concentrates because it’s not filtered too much. However, you still get to experience a good hit because you drag in the smoke just right.

How to measure the water level?

The easiest way to measure the water level is to look closely at your downstem. If it has slits, you need to make sure that your downstem and the slits are completely under water. No slit or gills? Submerge the downstem should be two inches above the opening for big bongs, or at least half an inch for mini bongs.

You can also rely on the bubbles and the sound they make when you inhale through the bong. There is a distinct, gurgling sound produced by the bubbles when the level of water is just right.

Why does water temperature matter?

The water temperature in your bong also affects your smoking experience in terms of cooling power, cleanliness, sensation, and health benefits.

  • Cooling power

    : The colder the water, the cooler the smoke. It’s safe to say that cooler is better to most cannabis consumers. Cutting the heat makes the smoke less irritating to the mucosa lining your mouth and respiratory tract – in other words, it’s gentler on the lungs and less likely to send you into coughing fits. But keep in mind that filling your piece with warm water is still going to cool the smoke. The temperature of the water is always going to be less than the burning bud in your bowl.

  • Cleanliness

    : One of the few downsides of filling your bong with icy-cold water is the resin build-up. THC solidifies faster in lower temperatures, leaving more resin behind on the innards of the piece. If you can’t stand to see those precious crystals go to waste (or you really hate cleaning your bong), cold water can work against you.

  • Sensation

    : You know that feeling you get when you press your palms around a warm mug of coffee? Toasting a glass of warm water is a lot like that. There’s something to be said for the feel of a warm bong giving off plumes of steamy smoke. Like a hot shower or a sauna room. Coldwater, on the other hand, tends to deliver thicker, more refreshing hits. The crispness of cool water enhances the freshness and flavor of the product.

  • Health benefits

    : If you’re aiming for the healthiest hit possible, water is definitely your friend. Filtering marijuana smoke through water lowers the amount of toxic substances while preserving most of its THC content. The reason is this: many of the harmful particles in marijuana smoke are water-soluble, while active ingredients like THC are not. The negative substances get trapped in the water while the good molecules pass through. Studies have also suggested marijuana smoke that has been filtered through water has less impact on the immune system than unfiltered smoke, which is good news for medical users.

How to measure the water temperature?

The simplest way to measure the water temperature is to use a thermometer. You can either dip it in the water or attach it to the side of the bong. The ideal temperature range for bong water is between 50 and 70 degrees Fahrenheit. Anything lower or higher than that can compromise the quality of your hit.

You can also adjust the water temperature by adding ice or warm water to your bong. Some bongs have ice holders/pinchers/catchers above the base or water chamber. As this melts, the water level at the base increases. However, if ice is added to the water chamber, the water level remains the same.


The water level and temperature in your glass bong are important factors that can enhance or diminish your smoking experience. By measuring them correctly, you can find the optimal balance of filtration, cooling, flavor, and health benefits. Remember to always change your bong water after each session and keep your bong clean for fresher tokes.