How to Make a Gravity Bong

Co-authored by wikiHow Staff

Last Updated: August 17, 2022 References Approved

A gravity bong is a fun and unique way to smoke cannabis. It's also super easy to make yourself. With just a few common household items, you can quickly make your very own gravity bong — just make sure you're using it in a place where smoking is legal.

Part 1

Part 1 of 3:

Making the Bowl

1
Find an empty plastic bottle. An empty water bottle or liter of soda will work. You can use any size bottle, but keep in mind that the bigger the bottle, the bigger the gravity bong hits will be.^{[1]
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- If you're smoking alone, a small plastic bottle should work. You may want a large plastic bottle if you're smoking with multiple people.
- Make sure the bottle you use can fit inside a second, larger plastic bottle or a bucket.
2
Take off the cap and cover the mouthpiece with aluminum foil. Don't wrap the aluminum foil around the mouthpiece too tightly. You'll need to take it off later when you're smoking out of the gravity bong. The entire opening should be covered with the aluminum foil.^{[2]
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3
Poke tiny holes in the aluminum foil over the mouthpiece. Use something thin to make the holes, like a toothpick or the end of a paper clip. Don't make too many holes or make the holes too big or the cannabis will fall down into the gravity bong. You just need a few holes so the smoke from the cannabis can travel down into the bottle.^{[3]
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Part 2

Part 2 of 3:

Making the Bong

1
Cut the bottom off the empty plastic bottle. First, gently pierce the bottle with a knife around 1–2 inches (2.5–5.1 cm) from the bottom. Then, insert a pair of scissors into the slit you made and cut around the bottle in a straight line until the bottom comes off. Set the top of the bottle aside for now and recycle the bottom.^{[4]
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2
Find a bucket or plastic container that's slightly larger than the bottle. This is the container you'll fill with water. You can also use another plastic bottle that's bigger than the first one. If you do, just cut off the neck of the bottle so the rim is the same width as the body.^{[5]
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3
Fill the larger plastic container with water. Cold or warm water is fine. You want to fill the container almost all the way up — leave 1–2 inches (2.5–5.1 cm) between the top of the water and the rim of the container.^{[6]
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Part 3

Part 3 of 3:

Using Your Gravity Bong

1
Put the bottle in the container of water. The open bottom of the bottle should be at the bottom of the container, and the neck and mouthpiece of the bottle should be at the top above the water. If water is covering the mouthpiece, you're pushing the bottle too far down in the container.^{[7]
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2
Sprinkle ground up cannabis over the holes in the aluminum foil. You can break up the cannabis using your fingers, or grind it up using a grinder. Don't grind it up too much or the pieces could fall through the holes.^{[8]
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- Hold the plastic bottle steady with one hand as you're putting the cannabis on the foil so it doesn't fall off.
3
Light the cannabis while slowly lifting up the plastic bottle. This will cause the bottle to fill up with smoke. Use one hand to hold the lighter and your other hand to lift up the bottle. Continue to hold the flame to the cannabis while you're lifting up the bottle.^{[9]
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4
Keep lifting the bottle until the bottom is almost out of the water. Don't lift the bottle all the way out of the water or all the smoke will escape. At this point, the entire bottle should be filled with smoke.^{[10]
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5
Take off the aluminum foil and put your mouth on the bottle. When you remove the foil, some smoke might escape. That's OK — just don't push down on the bottle or you'll force all of the smoke out.^{[11]
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6
Push down on the bottle slowly while inhaling. As you push the bottle down into the container, the smoke inside will be forced out and into your lungs. Don't push down too quickly or you could take in too much smoke. Keep inhaling and pushing down until all the smoke is out of the bottle.^{[12]
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- If you feel like you can't take in anymore smoke, take your mouth off the bottle.
7
Exhale the smoke from your lungs slowly. If there's more smoke in the plastic bottle, you can take another hit or push down on the bottle to clear it. When you're ready to use your gravity bong again, put the aluminum foil back on, sprinkle more cannabis over it, and repeat!^{[13]
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