Introducing the new Gravel Vac By JBJ called the Instant siphon gravel Cleaner. This unit is what you need to remove your old water from your aquarium.  The easy to prime Gravel Vacuum has a squeeze pump to self prime it.  No more getting aquarium water in your mouth.  Not like the old school Lee's Aquarium  Gravel Vacume i grew up with that i loved.  I think though they doi have a new on out.