yall are defeating the purpose of a gravity bong. Theyre made to put a very large amount of smoke deep into your lungs, causing you to get very high. Deeper in the lungs + larger instantaneous thc intake = Higher.
However I was thinking of something.
What if you took a normal gravity bong, but made the stem into around 4 stems, and had then run all the way to the bottom of the water. Then you pull up, causing the smoke to be filtered/cooled by the water. And maybe put some kind of intake valve on the bottom of the stems?