1.5 feet, mate if u wanted something to conceal from your parents dont you think it wouldve been smarter to get something smaller, my first couple of bongs were easy to hide,

my first one was shaped like yoda, i told my folks it was a money box, they bought it, i had it in plain site on my shelf, though i hid the pipes and cone piece.......

my second one was like a small glass jar, it had a rubber lid to put on tup then a cone piece and a small tube to breath from in there as well....

so yeah, buying a big one, while it may look impressive is pretty impractical and even stupid, next time go for something smaller.

for now though, get a backpack or some bag that you dont use anymore and that no one would ever miss, wrap ure bong up in old newspaper, put it in bag, hide bag in the back of your closet, or somewhere no one would see it......

you may also want to hide your cone piece and any other bits and pieces seperately, say one day u wanna smoke a bong but you cant get to yours for whatever reason, if you can get to the cone piece then all u gotta do is make a hole in a plastic bottle and your good to go