Our new Self-Start Siphon feature has made aquarium maintenance a whole lot easier!  With the Gravel Vacuum cylinder submerged in the water simply move it up and down a few times to activate the Self-Start Siphon.  Gravel Vacuum Cleaners are designed to separate and remove debris from the aquarium during routine water changes.  The Slim Jr. Gravel Vacuum Cleaner (# 11516) features a 1” diameter x 6” long cylinder with a 42” long hose and is ideal for large fish bowls and tanks with up to a 5 gallon capacity.  The Slim Gravel Vacuum Cleaner (#11549) features a 1-1/4” diameter x 12” long cylinder with a 42” long hose and is ideal for small aquariums and those hard-to-reach areas in most all aquariums.