You need to get a python, or some off brand version of it. It hooks to your sink, twist it one way, it sucks water in and you can do your gravel vac... twist it the other way, and it fills the tank back up.
I hate hex tanks, but you've done a very good job with yours.
"What, exactly, is the internet? Basically it is a global network exchanging digitized data in such a way that any computer, anywhere, that is equipped with a device called a 'modem', can make a noise like a duck choking on a kazoo." - Dave Barry