Just installed a 700 kit, this thing sounds like Niagra falls. Its a nice kit, I have lots of pics, but its hands down the loudest drain I have heard. there is no gulping, but the sound is similar to just having a 1 1/2" straight drain pipe free falling water. And to top it off, this morning my Nano light caught on fire and burned the canopy. Cant wait till my wife gets home.... new tank-with extremly loud drain topped off with the smell of burnt plastic in our house...Great....My cellphone will be ringing off the hook ! haha