well im not sher exactly what your looking for but a gravity bong is one of my favorits , i belive that it is also a good way to control the amount that you smoke , you can also employ this princeble in a bukket, the tub , fish tank, well youl get it

take a 3 litter soda bottel , cut off the top , now take a 2 litter bottel and cut off the bottom , take the cap (of the 2 leader ) and dril a hole that is big enuf to to fit the stem of your bowl through , now fil the 3 litter with watter (be carful of spilige ) then drop the 2 litter in