The tube with plastic hose extension, becomes a Gravity Siphon. It's how people steal gas. You suck on the end to get the water flowing ( careful, don't want a mouthful) then drop the end of the hose into a bucket that is below the water line in the tank, keep the viv end as firmly planted on the bottom of the viv as possible. Gravity will continue to pull the water out until it hits the bottom or the end lifts and air is allowed to enter. Might wanna try it using clean water from a glass of water for practice....GL!how am i supposed to pump it out..