Haven't thought of Gravity bongs in years lol. They were pretty nice tho. 4L water jugs were the best
Make sure you use a hooka stem:
I did it wrong my entire teenage years. The hooka stem lets it bubble up through the sink water and still act like a bong. Literally no one else I know figured this shit out.
So my good buddy was a fucking supreme loser. Sure, it sucks for him, but the weed R&D I gained from his broke-ass, nothing-but-free-time-having-ass was worth it's weight in dope. The dude seriously came up with some pot magic. This same motherfucker used to crack a couple of elpo's and roll serious corona-sized blunts for the room. It's amazing what you can do with your free time when your rich-ass folks are paying your bills.