Designing ya own bong isn't always as easy as ya might think i designed a bong system that uses baby bottles one time (plastic >.< yack,nasty). The idea was you took the cap off the baby bottle and glued it onto the bottom that wayyou could stack as many 'chambers' on top of each other as you liked. Each baby bottle had 3 bendy tubes fed in though the bottles just bellow the neck of the bottles that ended up in the water. This seemed to work fine for 2 bottles but when i made one that was 4 chambers high lol.The downpipe was in the bottom chamber which fed to the 2nd down , then the 2nd from the bottom and finaly into the top chamber. It took a huge length of pipes to connect it all up and looked pretty cool with them all twisted round the outside. Strange things started to happen. Water would start to flow up the pipes the wrong way O_o or a higher chamber would slowly suck all the water from a lower chamber. This was a real pain in the ass because of all the dam tube ya had to keep unhooking to set the water right again. I gave up in the end and made a self lighting bong instead .lol